* thread #​1: tid = 6673, 0x00007ffff7c2298c libswiftCore.so`swift::ValueWitnessFlags::getAlignmentMask(this=0x0000000000000090) const + 12 at Metadata.h:229, name = 'TestFoundation', stop reason = signal SIGSEGV: invalid address (fault address: 0x90)
    frame #​0: 0x00007ffff7c2298c libswiftCore.so`swift::ValueWitnessFlags::getAlignmentMask(this=0x0000000000000090) const + 12 at Metadata.h:229
   226    /// For example, if the type needs to be 8-byte aligned, the
   227    /// appropriate alignment mask should be 0x7.
   228    size_t getAlignmentMask() const {
-> 229      return (Data & AlignmentMask);
   230    }
   231    constexpr ValueWitnessFlags withAlignmentMask(size_t alignMask) const {
   232      return ValueWitnessFlags((Data & ~AlignmentMask) | alignMask);
(lldb) bt
* thread #​1: tid = 6673, 0x00007ffff7c2298c libswiftCore.so`swift::ValueWitnessFlags::getAlignmentMask(this=0x0000000000000090) const + 12 at Metadata.h:229, name = 'TestFoundation', stop reason = signal SIGSEGV: invalid address (fault address: 0x90)
  * frame #​0: 0x00007ffff7c2298c libswiftCore.so`swift::ValueWitnessFlags::getAlignmentMask(this=0x0000000000000090) const + 12 at Metadata.h:229
    frame #​1: 0x00007ffff7c2296c libswiftCore.so`swift::ValueWitnessTable::getAlignmentMask(this=0x0000000000000000) const + 28 at Metadata.h:731
    frame #​2: 0x00007ffff7c228e6 libswiftCore.so`swift::SwiftError::getValue(this=0x0000000000aefa60) const + 102 at ErrorObject.h:119
    frame #​3: 0x00007ffff7c4c56d libswiftCore.so`swift_getErrorValue(errorObject=0x0000000000aefa60, scratch=0x00007fffffffcf18, out=0x00007fffffffcf00) + 29 at ErrorObjectNative.cpp:106
    frame #​4: 0x00000000004954bd TestFoundation`TestNSData.test_sr1547(self=0x0000000000a65720) -> () + 301 at TestNSData.swift:101

do {
    throw NSError(domain: NSPOSIXErrorDomain, code: Int(123), userInfo: nil)
} catch {
    print(error)
}