Fix race between JIT executing emulated code and another image starting.

[andreiw]

More silent corruption due to lack of reentrance. But it's not enough to wrap uc_mem_protect...interrupts can be re-enabled inside JITted code (or really anytime) due to TPL manipulation, so need to hook the EFI_CPU_ARCH_PROTOCOL interrupt manipulation routines.

Very much reaching the point where a better JIT needs to be written that doesn't have the reentrancy issues.