[libclang] Make clang_findReferencesInFile also work on macros (find all expansions/definition
of a macro in a file).

As a bonus, also make searching for declarations more efficient by ignoring
preprocessing entities when we know that we are looking for a declaration.

Fixes rdar://10427411.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145369 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed