Fix to clang include on OS X.

src/source.cc

@@ -1427,7 +1427,7 @@ std::vector<std::string> Source::ClangViewParse::get_compilation_commands() {
   if(std::regex_match(clang_version_string, sm, clang_version_regex)) {
     auto clang_version=sm[1].str();
     arguments.emplace_back("-I/usr/lib/clang/"+clang_version+"/include");
-    arguments.emplace_back("-I/usr/local/lib/clang/"+clang_version+"/include");
+    arguments.emplace_back("-I/usr/local/Cellar/llvm/"+clang_version+"/lib/clang/"+clang_version+"/include");
     arguments.emplace_back("-IC:/msys32/mingw32/lib/clang/"+clang_version+"/include");
     arguments.emplace_back("-IC:/msys32/mingw64/lib/clang/"+clang_version+"/include");
     arguments.emplace_back("-IC:/msys64/mingw32/lib/clang/"+clang_version+"/include");