[9fans] lstk() in acid limited due to no type information

[9fans] lstk() in acid limited due to no type information

[erik quanstrom]

i don't use acid a lot in situations where this makes any
difference, so i hadn't noticed this until now.  but lstk()
backtraces can't do the right thing because they don't know how
much of each uintptr-sized stack element is actually used.
assuming 4 bytes often works for 32-bit machines since pointers
look correct.  unfortunately, on 64-bit machines, pointers are
mangled.  printing 8 bytes at a time unfortunately mangles all
32-bit values on the stack since the upper 32-bits don't have any
defined value.  a.out(6) mentions the issue, and suggets 8c(1)'s
-a flag, but this is of no use for backtraces since the compiler
doesn't information for local variables.

does anyone have ideas on how to work around this issue?

- erik