[CMake] Don't pass -fPIC when compiling the darwin builtins

This change makes CMake match autoconf.

llvm-svn: 252547
diff --git a/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
index c6bfbea..3706298 100644
--- a/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
@@ -264,7 +264,7 @@
     set(CMAKE_CXX_FLAGS_${CMAKE_BUILD_TYPE} -O3)
   endif()
 
-  set(CMAKE_C_FLAGS "-fPIC -fvisibility=hidden -DVISIBILITY_HIDDEN -Wall -fomit-frame-pointer")
+  set(CMAKE_C_FLAGS "-fvisibility=hidden -DVISIBILITY_HIDDEN -Wall -fomit-frame-pointer")
   set(CMAKE_CXX_FLAGS ${CMAKE_C_FLAGS})
   set(CMAKE_ASM_FLAGS ${CMAKE_C_FLAGS})