Attachment: Download

Issue Description:

Create a Swift Package using

```
swift-tools-version:5.3

```

Add a folder that contains a dot in the name, e.g. "Sample-1.0.0".

Optionally add source files to it.

Expectation:

Package can be built.

Actual:

Package loading fails (at least in Xcode) with:

: found 1 file(s) which are unhandled; explicitly declare them as resources or exclude from the target
<Project Path>/Sample-1.0.0

**It seems like the package manager mistakenly sees the folder as a file.

I attached a sample project that showcases the issue.