[llvm-objdump] Print source when subsequent lines in the translation unit come...

[llvm-objdump] Print source when subsequent lines in the translation unit come from the same line in two different headers.

Reviewers: grimar, rupprecht, jhenderson

Reviewed By: grimar, jhenderson

Subscribers: llvm-commits, jhenderson

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62461

llvm-svn: 362771