Merge #58: cmake: Skip superfluous PIC/PIE warning for Windows

52447c3 fixup! cmake: Add position independent code support (Hennadii Stepanov)

Pull request description:

  PIC/PIE is not a thing in Windows PE format. Therefore, warnings are rather making noise than providing valuable feedback.

ACKs for top commit:
  TheCharlatan:
    ACK 52447c3

Tree-SHA512: f7d3c134d72ff2148de551b287e9ae53e8a4d3ac6ee176cddc92bb21eeaca3cd892f53e1d6b143d7114e0a937982c72bd5429ba42be0883b4f79877989c85af4

CMakeLists.txt

@@ -80,7 +80,8 @@ include(CheckPIESupported)
 check_pie_supported(OUTPUT_VARIABLE check_pie_output LANGUAGES CXX)
 if(CMAKE_CXX_LINK_PIE_SUPPORTED)
   set(CMAKE_POSITION_INDEPENDENT_CODE ON)
-else()
+elseif(NOT WIN32)
+  # The warning is superfluous for Windows.
   message(WARNING "PIE is not supported at link time: ${check_pie_output}")
   list(APPEND configure_warnings "Position independent code disabled.")
 endif()