Fix a deadlock on the interrupt guard machinery.
* mini-exceptions.c (mono_walk_stack): Change the do_il_offset
parameter into unwind_options which is an enum that allows
multiple options to be passed.
* mini-exceptions.c (mono_jit_walk_stack_from_ctx): Ditto.
* mini.h: Introduce MonoUnwindOptions which allow stack
unwinding callers to specify that they don't want precise
method lookup (IOW, no need to deal with gsharing) which
allow those functions to be signal safe.
* mini-exceptions.c (mono_install_handler_block_guard): Ask
mono_walk_stack to perform signal safe unwinding.
Fixes #662741