Patch moves HandleSIGSEGV in HostFactory.cpp to a non-frontend host signal handler, then registers its own frontend signal handler to catch unhandled segfaults.
Both x86 and AArch64 support converting from one sized GPR to another
sized FPR. Expose it in our IR op.
Fixes a bug in CVTSI2SS with a 64bit source and it was treating the
input source as a 32bit value.
eg:
0x0000'0000'FFFF'FFFF was treated as converting to -1 float, which was wrong since it is a 64bit value
Sadly these things can't be split without breaking functionality so it
turns in to a bit of a mess.
SyscallHandler is very much something that is a Linux only construct and
shouldn't be in FEXCore itself. Lets the frontend register a
Syscallhandler with FEXCore. FEXCore itself is then aware of the current
syscall ABI and handles the ABI in an optimal fashion.
So it is not a 100% clean break otherwise we would lose performance.
The SignalDelegator then needs to move to the frontend since the
SyscallHandler requires it for signal based syscalls.
The CPU backend signal handling still needs to happen in FEXCore because
it is a very tight coupling with the CPU backend.
Once we need to support more Signal handling we can give the backends
cleaner support to select which specific OS handler to handle.
For the ones that should be IGNORE we can safely ignore them at that
point.
For the ones that have a default behaviour of crashing, just go ahead
and crash.
This was having the fun problem space that if we received an ignore
event, we would remove the fault handler then if the guest registered a
handler it would have never been called.
SIGWINCH specifically is one that defaults to ignore and we need to care
about. If SIGWICH happened before the guest registered a handler then it
would never receive the signal.
The ones that their default behaviour is faulting are fine to uninstall
and then immediately crash, since it is a real crash at that point.
This was causing issues in 32bit xeyes.
A couple of the multiply ops were still using 8bit and 16bit multiply
while the other one was already sexting or zexting the source.
