Display stack layout

[philipc]

Use DWARF locations to determine the stack layout.

[jrmuizel]

This seems like it would be quite valuable. I don't know of any other tool that exposes this kind of information.

[philipc]

This is partially done using DW_OP_fbreg and DW_OP_call_frame_cfa in location expressions. To do better, I think I need to also handle DW_OP_breg*, but for that I also need to determine how the base register relates to the stack frame... maybe this can be determined by getting the CFA from the CFI. Also, need to investigate how complete this information is going to be... there's big holes in the current output, and I don't think that DW_OP_breg* will be enough to fix that.

[philipc]

If you just want the stack size, there's also https://github.com/japaric/stack-sizes/