SIGWINCH is actually different for these architectures on Linux
according to the signal(7) man page.
Note: AFAICS there's no parisc machine in the GCC Farm[1],
so it remains untested. I've only tested mips64 for mips,
but I expect them to both work.
OpenBSD (on gcc231) octeon defines SIGWINCH as the common `28',
so it appears Linux is the only one with arch-dependent signal
numbers (ditto with syscalls).