[RFA] procfs.c: TARGET_CAN_USE_HARDWARE_WATCHPOINT via target vector

[Andrew Cagney]

> +#ifndef TARGET_HAS_HARDWARE_WATCHPOINTS

I just think the macro should be `largely' renamed: 
``PROCFS_HAS_HARDWARE_WATCHPOINTS''.

Largely?  There are a few exceptions -- i386v-nat.c and mips/tm-embed.h 
which could be left alone.

enjoy,
Andrew