Merging r340839:

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r340839 | bcain | 2018-08-28 18:23:39 +0200 (Tue, 28 Aug 2018) | 14 lines

[debuginfo] generate debug info with asm+.file

Summary:
For assembly input files, generate debug info even when the .file
directive is present, provided it does not include a file-number
argument.  Fixes PR38695.

Reviewers: probinson, sidneym

Subscribers: aprantl, hiraditya, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D51315


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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_70@341036 91177308-0d34-0410-b5e6-96231b3b80d8