[libclang] Add missing return in clang_getExpansionLocation that resulted in that function
always returning a null file/line/column.

Also add at least one use of clang_getExpansionLocation inside c-index-test that would have
made the tests to catch that.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143606 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed