build: support a non-standard library prefix for Windows (#1143)

In preparation for supporting static library linking on Windows, we are
adjusting the library naming convention for static Swift libraries,
preferring to use `lib<name>.lib` to differentiate them from the import
library for a dynamic variant of the same library. This mechanism is
already known to be used by Microsoft for ucrt (`ucrt.lib` vs
`libucrt.lib`), and was previously used in Swift as well for the C++
interop libraries.

Author: compnerd

Sources/FoundationEssentials/CMakeLists.txt

@@ -96,7 +96,7 @@ if(NOT BUILD_SHARED_LIBS)
     target_compile_options(FoundationEssentials PRIVATE
         "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -public-autolink-library -Xfrontend _FoundationCShims>")
     target_compile_options(FoundationEssentials PRIVATE
-        "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -public-autolink-library -Xfrontend _FoundationCollections>")
+        "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -public-autolink-library -Xfrontend $<$<PLATFORM_ID:Windows>:${CMAKE_STATIC_LIBRARY_PREFIX_Swift}>_FoundationCollections>")
     target_compile_options(FoundationEssentials PRIVATE
         "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -public-autolink-library -Xfrontend swiftSynchronization>")
 endif()