JIT: genericize immediate address handling, support in float stores too
JIT: fix register preloading

Partially broken by typoes in the bitset patch.
Merge pull request #1492 from FioraAeterna/fixregpreload

JIT: fix register preloading
Merge pull request #1230 from FioraAeterna/constaddr

JIT: improve handling of stores with a known address
PowerPC: Remove unused variable.
Merge pull request #1498 from rohit-n/unused

PowerPC: Remove unused variable.
TexCache: Wipe pal hash
TexCache: don't load tex level 0 on creation

This reverts an optimization which isn't worth imo. Every texture uploads have to alloc vram and a staging buffer, so there is no need to do both in the same call.
TexCache: remove expanded_width

This variable isn't use any more.