[llvm] [DebugInfo][NVPTX] Adding support for `inlined_at` debug directive in NVPTX backend (PR #170239)

[Jeremy Morse via llvm-commits]

https://github.com/jmorse commented:

I've gone through and pointed out some nits, there's nothing major to report, although I'm not as familiar with the MC layers of LLVM,

Like David I couldn't work out what's going on with the `InlinedAtLocs` situation or why it needs state across a function. I haven't looked at the tests yet: it might be easier if you can convert them to MIR tests that start immediately before code emission, and add some of the output fragments to the CHECK lines. That way a) the inputs won't be sensitive to changes through the rest of the codegen pipeline, which is a generally good thing, and b) we'll be able to interpret what instructions are covered by which .loc directives and how they order, which'll help us understand what the `InlinedAtLocs` state is doing.

https://github.com/llvm/llvm-project/pull/170239