Granularity of Stack layouts

[ekpyron]

[copied from matrix]
For the stack layouts, I'm wondering if it is necessary to produce them at the same granularity as source maps or whether that's excessive. Tooling/debuggers should be able to transport stack layouts across swaps etc. themselves, so I'm wondering if it's enough for the compiler to produce full stack layouts at relevant points in which simple tracing is no longer enough. We can generate this information for each opcode, so this is mainly a tradeoff in the verbosity of this information.

[gnidan]

Seems like generally specifying the entire layout is not unacceptable, but perhaps we can save some space by indicating certain kinds of stack modifications in part. Sounds like we still need to decide on specific behavior though.