S/390: PR79895: Fix TImode constant handling

S/390: PR79895: Fix TImode constant handling

The P constraint letter is supposed to match every constant which is
acceptable during reload.  However, constraints do not appear to be
able to handle const_wide_int yet.  It works with predicates so the
alternative is modelled with a new predicate now.

gcc/ChangeLog:

2017-04-25  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	PR target/79895
	* config/s390/predicates.md (reload_const_wide_int_operand): New
	predicate.
	* config/s390/s390.md ("movti"): Remove d/P alternative.
	("movti_bigconst"): New pattern definition.

gcc/testsuite/ChangeLog:

2017-04-25  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	PR target/79895
	* gcc.target/s390/pr79895.c: New test.

From-SVN: r247133