S/390: Make constant checking more strict

S/390: Make constant checking more strict

gcc/ChangeLog:

2015-12-02  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* config/s390/predicates.md (const_mask_operand): New predicate.
	* config/s390/s390-builtins.def: Set a smaller bitmask for a few builtins.
	* config/s390/vector.md: Change predicate from immediate_operand
	to either const_int_operand or const_mask_operand.  Add special
	insn conditions on patterns which have to exclude certain values.
	* config/s390/vx-builtins.md: Likewise.

From-SVN: r231159