[llvm] [MC] Fix DWARF file table for files with empty DWARF (#119020) (PR #119229)

[Eric Astor via llvm-commits]

ericastor wrote:

It doesn't seem like it would be bad to include this in MasmParser.cpp as well? It is true that it was forked from AsmParser.cpp... but also, I'm not sure if a test case is feasible, since (as mentioned) it's really designed for targeting Windows. I'll let @rnk weigh in on whether it'd be worthwhile.

https://github.com/llvm/llvm-project/pull/119229