IBM Z: Fix error checking for builtin vec_permi

IBM Z: Fix error checking for builtin vec_permi

The builtin vec_permi is peculiar in that its immediate operand is
encoded differently than the immediate operand that is backing the
builtin. This fixes the check for the immediate operand, adding a
regression test in the process.

This partially reverts commit 3191c1f4488d1f7563b563d7ae2a102a26f16d82

2021-05-06  Marius Hillenbrand  <mhillen@linux.ibm.com>

gcc/ChangeLog:

	* config/s390/s390-builtins.def (O_M5, O1_M5, ...): Remove unused macros.
	(s390_vec_permi_s64, s390_vec_permi_b64, s390_vec_permi_u64)
	(s390_vec_permi_dbl, s390_vpdi): Use the O3_U2 type for the immediate
	operand.
	* config/s390/s390.c (s390_const_operand_ok): Remove unused
	values.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/zvector/imm-range-error-1.c: Fix test for
	__builtin_s390_vpdi.
	* gcc.target/s390/zvector/vec-permi.c: New test for builtin
	vec_permi.