Issue Description:

symbolicate-linux-fatal tool is designed to ingest stdin, similarly to `swift demangle`. However, only the first stack trace detected in the input stream is symbolicated correctly. The other ones are corrupt. An example attached below.

Current stack trace:
0 libswiftCore.so 0x00007fe5aa7b37d6 swift_slowAlloc + 6
1 libswiftCore.so 0x00007fe5aa7b3818 swift_allocObject + 24
2 somesrv-app 0x0000000000cb7784 NIO.SocketChannel.__allocating_init(socket: NIO.Socket, parent: Swift.Optional<NIO.Channel>, eventLoop: NIO.SelectableEventLoop) throws -> NIO.SocketChannel + 68 at SocketChannel.swift:0
3 somesrv-app 0x0000000000cbe0e2 NIO.ServerSocketChannel.readFromSocket() throws -> NIO.BaseSocketChannel<NIO.ServerSocket>.ReadResult + 1170 at SocketChannel.swift:416
4 somesrv-app 0x0000000000b838eb NIO.BaseSocketChannel.(readable0 in _9C3D3FC8F9F3D83A05D3F6063F6AE958)() -> NIO.BaseSocketChannel<A>.(ReadStreamState in _9C3D3FC8F9F3D83A05D3F6063F6AE958) + 939 at BaseSocketChannel.swift:898
5 somesrv-app 0x0000000000b852ed NIO.BaseSocketChannel.readable() -> () + 317 at BaseSocketChannel.swift:882
6 somesrv-app 0x0000000000b86959 protocol witness for NIO.SelectableChannel.readable() -> () in conformance <A where A: NIO.BaseSocket> NIO.BaseSocketChannel<A> : NIO.SelectableChannel in NIO + 9 at BaseSocketChannel.swift:0
7 somesrv-app 0x0000000000c0891f NIO.SelectableEventLoop.(handleEvent in _D5D78C61B22284700B9BD1ACFBC25157)<A where A: NIO.SelectableChannel>(NIO.SelectorEventSet, channel: A) -> () + 735 at EventLoop.swift:441
8 somesrv-app 0x0000000000c09a96 closure #&#8203;1 (NIO.SelectorEvent<NIO.NIORegistration>) -> () in closure #&#8203;1 () throws -> () in NIO.SelectableEventLoop.run() throws -> () + 262 at EventLoop.swift:488
9 somesrv-app 0x0000000000c139b6 partial apply forwarder for closure #&#8203;1 (NIO.SelectorEvent<NIO.NIORegistration>) -> () in closure #&#8203;1 () throws -> () in NIO.SelectableEventLoop.run() throws -> () + 54 at EventLoop.swift:0
10 somesrv-app 0x0000000000c09be0 reabstraction thunk helper from @callee_owned (@owned NIO.SelectorEvent<NIO.NIORegistration>) -> (@error @owned Swift.Error) to @callee_owned (@in NIO.SelectorEvent<NIO.NIORegistration>) -> (@error @owned Swift.Error) + 64 at EventLoop.swift:0
11 somesrv-app 0x0000000000c13a53 partial apply forwarder for reabstraction thunk helper from @callee_owned (@owned NIO.SelectorEvent<NIO.NIORegistration>) -> (@error @owned Swift.Error) to @callee_owned (@in NIO.SelectorEvent<NIO.NIORegistration>) -> (@error @owned Swift.Error) + 83 at EventLoop.swift:0
12 somesrv-app 0x0000000000c96c7b NIO.Selector.whenReady(strategy: NIO.SelectorStrategy, (NIO.SelectorEvent<A>) throws -> ()) throws -> () + 5739 at Selector.swift:539
13 somesrv-app 0x0000000000c0991a closure #&#8203;1 () throws -> () in NIO.SelectableEventLoop.run() throws -> () + 234 at EventLoop.swift:494
14 somesrv-app 0x0000000000c0ff2e partial apply forwarder for closure #&#8203;1 () throws -> () in NIO.SelectableEventLoop.run() throws -> () + 78 at EventLoop.swift:0
15 somesrv-app 0x000000000043d9e6 reabstraction thunk helper from @callee_owned () -> (@error @owned Swift.Error) to @callee_owned () -> (@out (), @error @owned Swift.Error) + 22 at Await.swift:0
16 somesrv-app 0x0000000000c0ffd3 reabstraction thunk helper from @callee_owned () -> (@error @owned Swift.Error) to @callee_owned () -> (@out (), @error @owned Swift.Error)partial apply forwarder with unmangled suffix ".37" + 83 at EventLoop.swift:0
17 somesrv-app 0x0000000000c04727 NIO.(withAutoReleasePool in _D5D78C61B22284700B9BD1ACFBC25157)<A>(() throws -> A) throws -> A + 71 at EventLoop.swift:258
18 somesrv-app 0x0000000000c08eaf NIO.SelectableEventLoop.run() throws -> () + 671 at EventLoop.swift:495
19 somesrv-app 0x0000000000c0c298 closure #&#8203;1 (NIO.Thread) -> () in static NIO.MultiThreadedEventLoopGroup.(setupThreadAndEventLoop in _D5D78C61B22284700B9BD1ACFBC25157)(name: Swift.String, initializer: (NIO.Thread) -> ()) -> NIO.SelectableEventLoop + 616 at EventLoop.swift:674
20 somesrv-app 0x0000000000c132fc partial apply forwarder for closure #&#8203;1 (NIO.Thread) -> () in static NIO.MultiThreadedEventLoopGroup.(setupThreadAndEventLoop in _D5D78C61B22284700B9BD1ACFBC25157)(name: Swift.String, initializer: (NIO.Thread) -> ()) -> NIO.SelectableEventLoop + 156 at EventLoop.swift:0
21 somesrv-app 0x0000000000c0c8af reabstraction thunk helper from @callee_owned (@owned NIO.Thread) -> () to @callee_owned (@in NIO.Thread) -> (@out ()) + 15 at EventLoop.swift:0
22 somesrv-app 0x0000000000cd506a partial apply forwarder for reabstraction thunk helper from @callee_owned (@owned NIO.Thread) -> () to @callee_owned (@in NIO.Thread) -> (@out ()) + 74 at Thread.swift:0
23 somesrv-app 0x0000000000cd3e0b closure #&#8203;1 (Swift.Optional<Swift.UnsafeMutableRawPointer>) -> Swift.Optional<Swift.UnsafeMutableRawPointer> in static NIO.Thread.spawnAndRun(name: Swift.Optional<Swift.String>, body: (NIO.Thread) -> ()) -> () + 2395 at Thread.swift:105
24 somesrv-app 0x0000000000cd3eb9 @objc closure #&#8203;1 (Swift.Optional<Swift.UnsafeMutableRawPointer>) -> Swift.Optional<Swift.UnsafeMutableRawPointer> in static NIO.Thread.spawnAndRun(name: Swift.Optional<Swift.String>, body: (NIO.Thread) -> ()) -> () + 9 at Thread.swift:0
25 libpthread-2.19.so 0x00007fe5aa12c182 start_thread + 194
26 libc-2.19.so 0x00007fe5a816047d clone + 109
Stack count: 1
Leak size: 56 bytes
Current stack trace:
0 libswiftCore.so 0x00007fe5aa7b37d6 swift_slowAlloc + 6
1 libswiftCore.so 0x00007fe5aa7b3818 swift_allocObject + 24
2 libswiftCore.so 0x00007fe5aa46ebce Swift._ContiguousArrayBuffer.init(_uninitializedCount: Swift.Int, minimumCapacity: Swift.Int) -> Swift._ContiguousArrayBuffer<A> + 126
3 libswiftCore.so 0x00007fe5aa49a115 static Swift.Array._copyBuffer(inout Swift._ContiguousArrayBuffer<A>) -> () + 53
4 libswiftCore.so 0x00007fe5aa46e6eb Swift.ContiguousArray.subscript.nativePinningMutableAddressor : (Swift.Int) -> A + 187
5 libswiftCore.so 0x00007fe5aa46e8cb Swift.ContiguousArray.subscript.setter : (Swift.Int) -> A + 27
6 libswiftCore.so 0x00007fe5aa46f65c protocol witness for Swift.MutableCollection.subscript.setter : (A.Index) -> A.Element in conformance <A> Swift.ContiguousArray<A> : Swift.MutableCollection in Swift + 12
7 libswiftCore.so 0x00007fe5aa47067c (extension in Swift):Swift.MutableCollection.swapAt(A.Index, A.Index) -> () + 524
8 somesrv-app 0x0000000000c39bf8 closure #&#8203;1 (SomeServerProtobuf.Rpcproto_Response.(_StorageClass in _51F12C824C4B219132AD19C616B37C94)) throws -> () in SomeServerProtobuf.Rpcproto_Response.decodeMessage<A where A: SwiftProtobuf.Decoder>(decoder: inout A) throws -> () + 20168 at someserver.pb.swift:12242
9 somesrv-app 0x0000000000c3acf8 closure #&#8203;1 (SomeServerProtobuf.Rpcproto_Response.(_StorageClass in _51F12C824C4B219132AD19C616B37C94)) throws -> () in SomeServerProtobuf.Rpcproto_Response.decodeMessage<A where A: SwiftProtobuf.Decoder>(decoder: inout A) throws -> () + 24520 at someserver.pb.swift:12253
10 somesrv-app 0x0000000000c3a548 closure #&#8203;1 (SomeServerProtobuf.Rpcproto_Response.(_StorageClass in _51F12C824C4B219132AD19C616B37C94)) throws -> () in SomeServerProtobuf.Rpcproto_Response.decodeMessage<A where A: SwiftProtobuf.Decoder>(decoder: inout A) throws -> () + 22552 at someserver.pb.swift:12247
11 somesrv-app 0x0000000000c87c30 SomeServerProtobuf.Rpcproto_Response.AssetUpload.decodeMessage<A where A: SwiftProtobuf.Decoder>(decoder: inout A) throws -> () + 64 at someserver.pb.swift:0
12 somesrv-app 0x0000000000c0a0b9 SomeServerProtobuf.Rpcproto_Request.RetrieveRecord.(_StorageClass in _51F12C824C4B219132AD19C616B37C94).init(copying: SomeServerProtobuf.Rpcproto_Request.RetrieveRecord.(_StorageClass in _51F12C824C4B219132AD19C616B37C94)) -> SomeServerProtobuf.Rpcproto_Request.RetrieveRecord.(_StorageClass in _51F12C824C4B219132AD19C616B37C94) + 329 at someserver.pb.swift:11082
13 somesrv-app 0x0000000000c1005d protocol witness for SwiftProtobuf._MessageImplementationBase._protobuf_generated_isEqualTo(other: A) -> Swift.Bool in conformance SomeServerProtobuf.Rpcproto_Request.PartitionIds : SwiftProtobuf._MessageImplementationBase in SomeServerProtobuf + 285 at someserver.pb.swift:0
14 somesrv-app 0x000000000043d9e6 reabstraction thunk helper from @callee_owned () -> (@error @owned Swift.Error) to @callee_owned () -> (@out (), @error @owned Swift.Error) + -4194282 at Await.swift:0
15 somesrv-app 0x0000000000ce6663 initializeBufferWithCopyOfBuffer value witness for SomeServerProtobuf.Rpcproto_Request.RetrieveQuotaInfo + 19 at someserver.pb.swift:0
16 somesrv-app 0x0000000000ce3205 ___lldb_unnamed_symbol2234$$somesrv-app + 149 at someserver.pb.swift:0
17 somesrv-app 0x0000000000ce3344 ___lldb_unnamed_symbol2235$$somesrv-app + 100 at someserver.pb.swift:0
18 somesrv-app 0x0000000000c08fb1 SomeServerProtobuf.Rpcproto_Request.RecordRetrieveChanges.ChangeTypes._protobuf_nameMap.unsafeMutableAddressor : SwiftProtobuf._NameMap + 17 at someserver.pb.swift:11062
19 somesrv-app 0x0000000000c0c298 SomeServerProtobuf.Rpcproto_Request.RetrieveRecord._protobuf_generated_isEqualTo(other: SomeServerProtobuf.Rpcproto_Request.RetrieveRecord) -> Swift.Bool + 584 at someserver.pb.swift:11157
20 somesrv-app 0x0000000000c132fc SomeServerProtobuf.Rpcproto_Request.DsidToUserId.traverse<A where A: SwiftProtobuf.Visitor>(visitor: inout A) throws -> () + 172 at someserver.pb.swift:11339
21 somesrv-app 0x0000000000c0c8af closure #&#8203;1 (SomeServerProtobuf.Rpcproto_Request.RetrieveRecord.(_StorageClass in _51F12C824C4B219132AD19C616B37C94), SomeServerProtobuf.Rpcproto_Request.RetrieveRecord.(_StorageClass in _51F12C824C4B219132AD19C616B37C94)) -> Swift.Bool in SomeServerProtobuf.Rpcproto_Request.RetrieveRecord._protobuf_generated_isEqualTo(other: SomeServerProtobuf.Rpcproto_Request.RetrieveRecord) -> Swift.Bool + 1311 at someserver.pb.swift:11151
22 somesrv-app 0x0000000000cd506a ___lldb_unnamed_symbol2192$$somesrv-app + 218 at someserver.pb.swift:0
23 somesrv-app 0x0000000000cd3e0b initializeWithCopy value witness for SomeServerProtobuf.Rpcproto_Request + 91 at someserver.pb.swift:0
24 somesrv-app 0x0000000000cd3eb9 assignWithCopy value witness for SomeServerProtobuf.Rpcproto_Request + 137 at someserver.pb.swift:0
25 libpthread-2.19.so 0x00007fe5aa12c182 start_thread + 194
26 libc-2.19.so 0x00007fe5a816047d clone + 109