Adds support for UBFX to JIT and Disassembler

This introduces UBFX instruction generation abilities to the Pixelflinger JIT,
and also modifies the component extraction function to generate the
instruction.

The extract function contains defines to prevent generation of UBFX on pre-v7
cores. The JIT itself retains the ability to produce the instruction even on
v5/6.

This patch only generates UBFX when MOV, AND or BIC can't be used. Based on
the TRM, this appears to be faster on A9 than using UBFX in all cases.

On startup, Pixelflinger JITs three chunks of code. UBFX improves these as
follows:

 00000077:03515104_00000000_00000000
 (Blends a single colour into an RGB565 buffer.)
  Before: 27 inst/pixel, After: 24 inst/pixel, Improvement: 12.5%
 00000077:03545404_00000A01_00000000
 (Blends RGBA8888 texture into an RGB565 buffer using alpha.)
  Before: 30 inst/pixel, After: 27 inst/pixel, Improvement: 11.1%
 00000077:03545404_00000A04_00000000
 (Blends RGB565 texture into an RGB565 buffer using alpha.)
  Before: 29 inst/pixel, After: 27 inst/pixel, Improvement: 7.4%