regalloc: fix a few compiler warnings in xpoint.c
regalloc: fix a few compiler warnings in xpoint.c

Manage remaining xpoint types with new/delete, and fix a few compilation
warnings.

Signed-off-by: Nico Reißmann <d8255cca0642bdc1e6f9b45da9cb618d308e389b@gmail.com>

phate/jive,phate/jive,phate/jive