Windows: fix error D8016: '/O2' and '/RTC1' command-line options are incompatible

Author: emillaine

CMakeLists.txt

@@ -119,7 +119,8 @@ endif()
 
 # Optimize test utilities by default.
 if(MSVC)
-    set_target_properties(FileCheck PROPERTIES COMPILE_FLAGS "${LLVM_DEFINITIONS} -w /O2 /GL /MT")
+    string(REGEX REPLACE "/RTC[^ ]*" "" LLVM_DEFINITIONS "${LLVM_DEFINITIONS}") # Remove /RTC flags
+    set_target_properties(FileCheck PROPERTIES COMPILE_FLAGS "${LLVM_DEFINITIONS} /w /O2 /GL /MT")
     set_target_properties(libcx PROPERTIES COMPILE_FLAGS "/MT")
     set_target_properties(cx PROPERTIES COMPILE_FLAGS "/MT")
 else()