[OpenMP] Fix issue of indirect function call in `__kmpc_fork_call_if` (#65436)

The outlined function is typically invoked by using
`__kmp_invoke_microtask`,
which is written in asm. D138495 introduces a new interface function for
parallel
region for OpenMPIRBuilder, where the outlined function is called via
the function
pointer. For some reason, it works perfectly well on x86 and x86-64
system, but
doesn't work on Apple Silicon. The 3rd argument in the callee is always
`nullptr`, even
if it is not in caller. It appears `x2` always contains `0x0`. This
patch adopts
the typical method to invoke the function pointer. It works on my M2
Ultra Mac.

Fix #63194.