armjit: Verify free space while compiling.
armjit: keep track of instructions in jitstate.

To match x86.
armjit: Copy over (disabled) immbranch optim.

This does a little loop unrolling.  Costs a bit more cache space, but
avoids flushing regs for longer.

Not enabled.
x86/armjit: Add jump following (off by default.)

Inlines function calls up to a certain extent.  Allows us to get
immediates all the way to a syscall, for example, usually.

Not sure if faster.
x86jit: Rename imm funcs to match armjit.
x86/armjit: Stop compiling on a jump to invalid.
x86jit: Try predicting branch continues.

Still doesn't seem to work.  Something like a 4% gain in Star Ocean was
the best I saw...
Merge pull request #4506 from unknownbrackets/jit-continuing

Further attempts at continuing jit blocks (disabled)