[compiler-rt] Do not add -rpath to linker args on Windows

This is not supported. Should hopefully fix Windows CI after
commit c91254d.

Author: arichardson

compiler-rt/CMakeLists.txt

@@ -602,7 +602,9 @@ if (COMPILER_RT_TEST_STANDALONE_BUILD_LIBS)
     list(APPEND COMPILER_RT_UNITTEST_LINK_FLAGS "-resource-dir=${COMPILER_RT_OUTPUT_DIR}")
   endif()
   get_compiler_rt_output_dir(${COMPILER_RT_DEFAULT_TARGET_ARCH} rtlib_dir)
-  list(APPEND COMPILER_RT_UNITTEST_LINK_FLAGS "-Wl,-rpath,${rtlib_dir}")
+  if (NOT WIN32)
+    list(APPEND COMPILER_RT_UNITTEST_LINK_FLAGS "-Wl,-rpath,${rtlib_dir}")
+  endif()
 endif()
 
 if(COMPILER_RT_USE_LLVM_UNWINDER)