GHA: enable atomics module for Swift

Add `-D SWIFT_ENABLE_SYNCHRONIZATION=YES` to enable the new
synchronisation module which is packaged up in to the installer.

Author: compnerd

.github/workflows/swift-toolchain.yml

@@ -681,6 +681,7 @@ jobs:
                 -D SWIFT_ENABLE_EXPERIMENTAL_DIFFERENTIABLE_PROGRAMMING=YES `
                 -D SWIFT_ENABLE_EXPERIMENTAL_OBSERVATION=YES `
                 -D SWIFT_ENABLE_EXPERIMENTAL_STRING_PROCESSING=YES `
+                -D SWIFT_ENABLE_SYNCHRONIZATION=YES `
                 -D SWIFT_NATIVE_SWIFT_TOOLS_PATH=${{ github.workspace }}/BinaryCache/0/bin `
                 -D SWIFT_PATH_TO_LIBDISPATCH_SOURCE=${{ github.workspace }}/SourceCache/swift-corelibs-libdispatch `
                 -D SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE=${{ github.workspace }}/SourceCache/swift-syntax `
@@ -1151,6 +1152,7 @@ jobs:
                 -D SWIFT_ENABLE_EXPERIMENTAL_DIFFERENTIABLE_PROGRAMMING=YES `
                 -D SWIFT_ENABLE_EXPERIMENTAL_OBSERVATION=YES `
                 -D SWIFT_ENABLE_EXPERIMENTAL_STRING_PROCESSING=YES `
+                -D SWIFT_ENABLE_SYNCHRONIZATION=YES `
                 -D SWIFT_NATIVE_SWIFT_TOOLS_PATH=${{ github.workspace }}/BuildRoot/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin `
                 -D SWIFT_PATH_TO_LIBDISPATCH_SOURCE=${{ github.workspace }}/SourceCache/swift-corelibs-libdispatch `
                 -D SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE=${{ github.workspace }}/SourceCache/swift-syntax `