Added ARMv6T2 experiment.

These adds replacements for handlers that benefit from the use of new
instructions introduced in ARMv6T2 (notably UBFX, unsigned bit-field
extraction).  This also adds an "armv7-a" mterp config file.

The benchmark improvement was tiny, so there's no real motivation to
convince the build system to use them.

This also includes an interleave fix for binop2addr.
95 files changed