[Support] Fix WS2_32 casing

The file name is WS2_32.Lib in all the Windows SDK versions I looked at.
You can get away with the incorrect casing on a case-insensitive file
system but it can matter for cross-compilation.

Author: smeenai

llvm/lib/Support/CMakeLists.txt

@@ -40,7 +40,7 @@ endif()
 if( MSVC OR MINGW )
   # libuuid required for FOLDERID_Profile usage in lib/Support/Windows/Path.inc.
   # advapi32 required for CryptAcquireContextW in lib/Support/Windows/Path.inc.
-  set(system_libs ${system_libs} psapi shell32 ole32 uuid advapi32 Ws2_32)
+  set(system_libs ${system_libs} psapi shell32 ole32 uuid advapi32 WS2_32)
 elseif( CMAKE_HOST_UNIX )
   if( HAVE_LIBRT )
     set(system_libs ${system_libs} rt)

llvm/test/tools/llvm-config/system-libs.windows.test

@@ -2,6 +2,6 @@ RUN: llvm-config --link-static --system-libs Support 2>&1 | FileCheck %s
 REQUIRES: static-libs
 REQUIRES: host={{.*-windows-msvc}}
 CHECK-NOT: -l
-CHECK: psapi.lib shell32.lib ole32.lib uuid.lib advapi32.lib Ws2_32.lib{{$}}
+CHECK: psapi.lib shell32.lib ole32.lib uuid.lib advapi32.lib WS2_32.lib{{$}}
 CHECK-NOT: error
 CHECK-NOT: warning