Update for LLVM API change

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@222304 91177308-0d34-0410-b5e6-96231b3b80d8
Remove uses of StringMap::GetOrCreateValue in favor of stl-compatible API usage

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@222305 91177308-0d34-0410-b5e6-96231b3b80d8
Update for LLVM API change to make Small(Ptr)Set::insert return pair<iterator, bool> as per the C++ standard's associative container concept.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@222336 91177308-0d34-0410-b5e6-96231b3b80d8
[clang-tidy] Count errors in ClangTidyDiagnosticConsumer


git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@222363 91177308-0d34-0410-b5e6-96231b3b80d8
Revert r222363: "[clang-tidy] Count errors in ClangTidyDiagnosticConsumer"

This was causing clang-tidy invocations that would previously pass despite
source errors to fail.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@222390 91177308-0d34-0410-b5e6-96231b3b80d8