S/390: Fix vec_splat_* builtins.

S/390: Fix vec_splat_* builtins.

gcc/testsuite/ChangeLog:

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

	* gcc.target/s390/zvector/vec-splat-2.c: New test.

gcc/ChangeLog:

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

	* config/s390/s390-builtin-types.def: New builtin types added.
	* config/s390/s390-builtins.def: Add s390_vec_splat_* definitions.
	* config/s390/s390.c (s390_expand_builtin): Always truncate
	constants to the mode in the pattern.
	* config/s390/vecintrin.h: Let the vec_splat_* macros point to the
	respective builtin __builtin_s390_vec_splat_*.

From-SVN: r231157