Remove old out* code
Rename V_REG_SAVE to V_REG_SPILT
v_to_stack_mem() changes type to a spilt register
Keep val type/store in v_dup()
Keep type in out_val_overwrite()
Remove some old-backend #if-0'd code
Start of backend conditional branching
out_ctx passed to all out_asm() functions
out_asm*() add to a block's instruction vector
Basic block collation + flushing
Partial conditional control flow logic with basic blocks