Avoid using CALL() directly in case of far calls.

This mainly matters for x64.
This isn't needed if ABI_CallFunction* is used.

AFAICT the only reason for it is to avoid far calls, so we just can't
use CALL() directly.  It's works even when it throws on Mac.
Merge pull request #780 from unknownbrackets/jit-minor

Fix warning / test failure on Mac with x86 jit