Handle gcc-compatible compilers (such as clang) the same way we handle
gcc.

Fixes PR9886.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131181 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/modules/LLVMProcessSources.cmake b/cmake/modules/LLVMProcessSources.cmake
index 270292a..641f1b3 100644
--- a/cmake/modules/LLVMProcessSources.cmake
+++ b/cmake/modules/LLVMProcessSources.cmake
@@ -56,7 +56,7 @@
 
   # Set common compiler options:
   if( NOT LLVM_REQUIRES_EH )
-    if( CMAKE_COMPILER_IS_GNUCXX )
+    if( LLVM_COMPILER_IS_GCC_COMPATIBLE )
       add_definitions( -fno-exceptions )
     elseif( MSVC )
       llvm_replace_compiler_option(CMAKE_CXX_FLAGS "/EHsc" "/EHs-c-")
@@ -64,7 +64,7 @@
     endif()
   endif()
   if( NOT LLVM_REQUIRES_RTTI )
-    if( CMAKE_COMPILER_IS_GNUCXX )
+    if( LLVM_COMPILER_IS_GCC_COMPATIBLE )
       llvm_replace_compiler_option(CMAKE_CXX_FLAGS "-frtti" "-fno-rtti")
     elseif( MSVC )
       llvm_replace_compiler_option(CMAKE_CXX_FLAGS "/GR" "/GR-")