[libclang] Fix annotation of a range where the begin or end location
is inside a macro argument.

Previously we would give up and not annotate anything in the range.
rdar://11891550

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@175062 91177308-0d34-0410-b5e6-96231b3b80d8