[clang] [clang] Use File Location for debug info resolution. (PR #163982)

[Orlando Cazalet-Hyams via cfe-commits]

OCHyams wrote:

> But usually the reason to compile the binary with -g option is to have move debug info, not less. Why do we treat macro any different from other code.

There are plenty of flags to use alongside -g that limit debug info emission in some way, e.g. -gno-column-info.

> If the goal is to save on symbols table size, we can fold all source locations to the start of an enclosing scope for each symbol.

The goal is to understand and discuss the trade-offs, which is a common part of the review process.

My SGTM still stands, and David already approved this, but IMO it would be good to wait a little longer to see if one of the Apple/LLDB folks have any additional opinions on this.

https://github.com/llvm/llvm-project/pull/163982