Generalise the register reuse optimisation in v_unused_reg()
Only optimise non-pointer/stepped constant ops
Fix memory management for out_op() double constant
Correct type for bitfield-scalar-merge
Simplify value handling in out_normalise()
Fixed duplication of a out_val flag
Fix memory/val retaining in __builtin_memcpy()
for loop - break and continue blocks
Empty for loop code gen/block flow fix