[compiler-rt] Appending COMPILER_RT_LIBCXX_PATH -isystem include for xray (2)

Second attempt.

Haven't found a better way to pass the libcxx include path for building
compiler-rt with libcxx; this seems to be missing only for xray.

Differential Revision: https://reviews.llvm.org/D65307

llvm-svn: 367250

compiler-rt/lib/xray/CMakeLists.txt

@@ -118,6 +118,11 @@ endforeach()
 include_directories(..)
 include_directories(../../include)
 
+if(COMPILER_RT_USE_LIBCXX)
+  if (SANITIZER_CXX_ABI_LIBNAME STREQUAL "libc++")
+    set(SANITIZER_COMMON_CFLAGS "${SANITIZER_COMMON_CFLAGS} -isystem ${COMPILER_RT_LIBCXX_PATH}/include")
+  endif()
+endif()
 set(XRAY_CFLAGS ${SANITIZER_COMMON_CFLAGS})
 set(XRAY_COMMON_DEFINITIONS XRAY_HAS_EXCEPTIONS=1)