Handle Unicode characters in fix-it replacement strings.

Patch by Sukolsak Sakshuwong!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183535 91177308-0d34-0410-b5e6-96231b3b80d8
Improved handling of escaped newlines at the token start.

Summary: Remove them from the TokenText as well.

Reviewers: klimek

Reviewed By: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D935

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183536 91177308-0d34-0410-b5e6-96231b3b80d8
Thread the 'Invalid' out parameter through SourceManager::getSLocEntry() and callees of SourceManager::getSLocEntryByID().

Also add an 'Invalid' check in SourceManager::computeMacroArgsCache().

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183538 91177308-0d34-0410-b5e6-96231b3b80d8