[CMake] Explicitly set Android lib prefix/suffix

When compiling the Swift standard library for Android on Linux, the
target prefixes and suffixes for static and shared libraries happen to
be the same for both platforms. When using a macOS host to compile,
however, the suffixes are different, causing build errors.

Explicitly set the prefixes and suffixes to prevent errors when
building on macOS.

Author: modocache

cmake/modules/AddSwift.cmake

@@ -53,7 +53,15 @@ function(_set_target_prefix_and_suffix target kind sdk)
   precondition(kind MESSAGE "kind is required")
   precondition(sdk MESSAGE "sdk is required")
 
-  if("${sdk}" STREQUAL "WINDOWS")
+  if("${sdk}" STREQUAL "ANDROID")
+    if("${kind}" STREQUAL "STATIC")
+      set_property(TARGET "${target}" PROPERTY PREFIX "lib")
+      set_property(TARGET "${target}" PROPERTY SUFFIX ".a")
+    elseif("${libkind}" STREQUAL "SHARED")
+      set_property(TARGET "${target}" PROPERTY PREFIX "lib")
+      set_property(TARGET "${target}" PROPERTY SUFFIX ".so")
+    endif()
+  elseif("${sdk}" STREQUAL "WINDOWS")
     if("${kind}" STREQUAL "STATIC")
       set_property(TARGET "${target}" PROPERTY PREFIX "lib")
       set_property(TARGET "${target}" PROPERTY SUFFIX ".lib")