[mono][interp] Fix an issue with deopt and interpreter tiering. (#76743)

[mono][interp] Fix an issue with deopt and interpreter tiering. (#76743)

* [mono][interp] Fix an issue with deopt and interpreter tiering.

If a method is tiered while being run from interp_run_clause_with_il_state (),
the clause_args argument to interp_exec_method () still contains the old IL
offsets confusing the EH code, i.e. this line:
```
if (clause_args && frame == clause_args->exec_frame && context->handler_ip >= clause_args->end_at_ip)
```

Clear out clause_args at the beginning to avoid this.

Hopefully fixes
https://github.com/dotnet/runtime/issues/76134
https://github.com/dotnet/runtime/issues/74302

* [mono][interp] Avoid tiering up methods while running clauses.

The IL offsets in the clause_args argument become out-of-date after tiering up.