SanitizerBlacklist: Use spelling location for blacklisting purposes.

When SanitizerBlacklist decides if the SourceLocation is blacklisted,
we need to first turn it into a SpellingLoc before fetching the filename
and scanning "src:" entries. Otherwise we will fail to fecth the
correct filename for function definitions coming from macro expansion.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220403 91177308-0d34-0410-b5e6-96231b3b80d8