[RFC] Support command "catch syscall" properly on different targets

[Yao Qi]

Pedro Alves <palves@redhat.com> writes:

> Do we actually need to do anything when the inferior is created?
> Supposedly once the inferior is created, we'll try to insert
> the catchpoint, and that will fail is the target does not
> support it.

No, but we need to tweak test case to emit UNSUPPORTED instead of FAIL
if the target doesn't support "catch syscall".

-- 
Yao (齐尧)