Avoid CallSyscall() overhead from jit

Most of the things it does are affected by relatively static variables, or direct results of the parameters.  We can avoid all that by calling it directly from jit to the degree possible.

Cuts +/- 0.6% from profile in ClaDun on Android (~2.46% -> ~1.21% + ~0.44%)  Not huge but I had actually started it already, finished it since I saw it would probably matter a bit.

Also a sceKernelIsCpuIntrSuspended() fix, I don't have any games that actually call it though, but test results seem pretty clear.

-[Unknown]