* i386v4-nat.c: Include "i386-tdep.h". Reformat and tweak various

* i386v4-nat.c: Include "i386-tdep.h".  Reformat and tweak various
comments.
(fill_gregset, supply_gregset, supply_fpregset, fill_fpregset):
Remove prototypes.
(supply_gregset, fill_gregset): Remove use of register keyword and
remove declaration for regmap.  Use I386_NUM_GREGS instead of
NUM_REGS and NUM_FREGS.
(FPREGSET_FSAVE_OFFSET): Remove.
(supply_fpregset, fill_fpregset): Use FPO_REGNUM instead of
NUM_FREGS to determine whether the floating-point registers are
available.