[llvm] r174874 - AArch64: Add basic relocation processing for llvm-dwarfdump.

[Tim Northover]

> I'm of the opinion that dwarfdump test cases should, as much as
> possible, only test dwarfdump & thus your original version (with a
> binary file committed as the input).

That was the thinking behind my commit too. It was actually written
when AArch64 wasn't even being built by default so I definitely wanted
this tested wherever possible.

I'm rather more relaxed about that now, and would probably want to
know if the debugging information changed on a file like that,
regardless of whether it was llc or dwarfdump's fault.

> This way, we get a clear sense of when dwarfdump is broken (hey, the
> dwarfdump tests failed) as compared to when the product is broken
> (hey, the tests that use dwarfdump failed - the product must be
> broken)

A good idea in general, but I'm not convinced it applies to the
in-tree tests: they should always be passing no matter what. More
isolated tests help with debugging when failures *do* happen, of
course, but usually not that much. You know what's been poked recently
and running the steps manually is usually enough for when even that
fails.

Also just my vague thoughts.

Tim.