Tracking issue for -Z emit-stack-sizes

[japaric]

This is an experimental feature (i.e. there's no RFC for it) approved by the compiler team and added in #51946. It's available in nightly-2018-09-27 and newer nightly toolchains.

Documentation can be found in the unstable book.

[cramertj]

The flag implemented in #51946 is called emit-stack-sizes. This issue is "Tracking issue for -Z emit-stack-sections." Typo?

[japaric]

@cramertj yes, thanks! It has been fixed.

[tgross35]

Just curious, is there anything specific needed to eventually move this to stable? It seems like the feature is relatively simple and stable, just based on the lack of changes for the past four years

[workingjubilee]

This does not offer useful support for all targets, it is unclear if it ever will, and LLVM generally seems to consider their CLI interface to be unstable to a degree we are loathe to do, so I do not think we should offer another "expose random LLVM knobs" flag without a clear plan for making it more useful and supporting it in the absence of LLVM support.