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
videocommon: UpdateDrawRectangle cleanup
videocommon: fix spelling of width