https://bugs.llvm.org/show_bug.cgi?id=43722
GWP-ASan didn't include SANITIZER_COMMON_CFLAGS, and thus would produce
LLVM bitcode files, when compiler-rt is generally built without LTO.
# Ensure that GWP-ASan meets the delegated requirements of some supporting
# allocators. Some supporting allocators (e.g. scudo standalone) cannot use any
# parts of the C++ standard library.
-set(GWP_ASAN_CFLAGS -fno-rtti -fno-exceptions -nostdinc++ -pthread)
+set(GWP_ASAN_CFLAGS ${SANITIZER_COMMON_CFLAGS} -fno-rtti -fno-exceptions
+ -nostdinc++ -pthread)
append_list_if(COMPILER_RT_HAS_FPIC_FLAG -fPIC GWP_ASAN_CFLAGS)
append_list_if(COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG -fno-omit-frame-pointer
GWP_ASAN_CFLAGS)