8133456: HeapRegionManager::shrink_by() iterates suboptimally across regions
Reviewed-by: brutisso, tbenson
os_family = solaris
arch = sparc
arch_model = sparc
os_arch = solaris_sparc
os_arch_model = solaris_sparc
lib_arch = sparc
compiler = gcc
sysdefs = -DSOLARIS -D_GNU_SOURCE -DSPARC