* config/s390/s390.c (MIN_UNROLL_PROBES): Define.
(allocate_stack_space): New function, partially extracted from
s390_emit_prologue.
(s390_emit_prologue): Track offset to most recent stack probe.
Code to allocate space moved into allocate_stack_space.
Dump actions when no stack is allocated.
(s390_prologue_plus_offset): New function.
(s390_emit_stack_probe): Likewise.
* gcc.dg/stack-check-5.c: Add argument for s390.
* lib/target-supports.exp:
(check_effective_target_supports_stack_clash_protection): Enable for
s390/s390x targets.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@253049 138bc75d-0d04-0410-961f-82ee72b054a4