Fixes minor bug in the ARMv7 register cache.

Makes sure our register we are binding doesn't get unloaded immediately.
Fixes some overzealous optimizations from ARMv7 BindToRegister.

We can't do it in rlw and friends.
subfx had an inccorect check.
Minor whitespace and reordering.
Fixes a potential crash on the ARMv7 JIT if someone disables the entire JIT in the debugger.
We can't disable branches in the JITs. Make sure they don't become disabled if someone tries to disable the full JIT.
Merge pull request #1404 from Sonicadvance1/fix-ARMv7

Fixes some ARMv7 regressions.