[PATCH] Fix PCH on MIPS

[Andrew Pinski]

Since Linux 2.6.36, both the heap and mmap are randomized on MIPS like
other architectures. This breaks PCH because currently
TRY_EMPTY_VM_SPACE is not defined for MIPS.
This patch fixes the issue and allows largefile test to pass now.

OK? Bootstraped and tested on mips64-linux-gnu.

Thanks,
Andrew Pinski

ChangeLog:
* config/host-linux.c (TRY_EMPTY_VM_SPACE): Define for MIPS.