LLVM_ENABLE_MODULES: No need to set -fcxx-modules in trunk, just -fmodules.

llvm-svn: 252996
diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index db0abb6..82a4084 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -433,7 +433,7 @@
   endif()
   if (LLVM_ENABLE_MODULES)
     set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
-    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fmodules -fcxx-modules")
+    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fmodules")
     # Check that we can build code with modules enabled, and that repeatedly
     # including <cassert> still manages to respect NDEBUG properly.
     CHECK_CXX_SOURCE_COMPILES("#undef NDEBUG