* ggc-common.c (ggc_rlimit_bound): Don't check RSS limit.

	Check DATA limit only if there's no AS limit.  Ignore insanely
	low DATA limits.
	(ggc_min_heapsize_heuristic): Don't divide AS or RSS limits by 8,
	but take care that the AS limit isn't overrun.
	* doc/invoke.texi: Update documentation of min-heapsize parameter.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@85722 138bc75d-0d04-0410-961f-82ee72b054a4