Add udis86 b24baf1 (1.7.3?), not yet used.

Linked even on arm to avoid dependency complexity, might skip later.
Avoid some warnings in udis86.

These should all be safe.
Enable x86 disassembly in jit compare.
Avoid spinning the CPU in dev menu screens.
Merge pull request #6993 from unknownbrackets/udis86

Use udis86 as an x86 disassembler
Fix paths.

Hmm, this didn't happen when I added other things in ext... I blame 2013.