Update clang test to accomendate discriminator change in https://reviews.llvm.org/D25132

Summary: https://reviews.llvm.org/D25132 added discriminator even add -g0. This leads to test fail which is addressed in thie patch.

Reviewers: davidxl, dnovillo

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25133

llvm-svn: 283564