GHA: shuffle the Foundation headers

The installer rules are progressively assuming a fully staged toolchain.
We did not previously shuffle the C headers that Foundation expects into
the correct location. Do so to allow packaging with the updated
manifest.

Author: compnerd

Diff for: .github/workflows/swift-toolchain.yml

@@ -2437,6 +2437,8 @@ jobs:
         if: matrix.os != 'Android' || inputs.build_android
         run: |
           cmake --build ${{ github.workspace }}/BinaryCache/foundation --target install
+          Move-Item -Path "${{ github.workspace }}/BuildRoot/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk/usr/lib/swift/_foundation_unicode/" -Destination "${{ github.workspace }}/BuildRoot/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk/usr/include/"
+          Move-Item -Path "${{ github.workspace }}/BuildRoot/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk/usr/lib/swift/_FoundationCShims/" -Destination "${{ github.workspace }}/BuildRoot/Library/Developer/Platforms/${{ matrix.os }}.platform/Developer/SDKs/${{ matrix.os }}.sdk/usr/include/"
       - name: Install libdispatch
         if: matrix.os != 'Android' || inputs.build_android
         run: |