While using Clang from Homebrew on Mac OSX, ROOT picks wrong Clang headers

  [77%] Building CXX object core/metacling/src/CMakeFiles/MetaCling.dir/TClingCallbacks.cxx.o

In file included from /Users/ahmad/bdm-build-third-party/root/core/metacling/src/TClingCallbacks.cxx:37:

In file included from /Users/ahmad/bdm-build-third-party/root/core/metacling/src/ClingRAII.h:13:

/Users/ahmad/bdm-build-third-party/root/interpreter/cling/include/cling/Utils/ParserStateRAII.h:32:29: error: 'TemplateIds' is a private member of 'clang::Parser'

    decltype(clang::Parser::TemplateIds) OldTemplateIds;

                            ^

/usr/local/opt/llvm/include/clang/Parse/Parser.h:254:43: note: implicitly declared private here

  SmallVector<TemplateIdAnnotation *, 16> TemplateIds;

                                          ^

In file included from /Users/ahmad/bdm-build-third-party/root/core/metacling/src/TClingCallbacks.cxx:37:

/Users/ahmad/bdm-build-third-party/root/core/metacling/src/ClingRAII.h:60:29: error: no type named 'CleanupAndRestoreCacheRAII' in 'clang::Preprocessor'

       clang::Preprocessor::CleanupAndRestoreCacheRAII fCleanupRAII;

       ~~~~~~~~~~~~~~~~~~~~~^