S/390: Fix vector shift count operand

S/390: Fix vector shift count operand

We currently use subst definitions to handle the different variants of shift
count operands. Unfortunately, in the vector shift pattern the shift count
operand is used directly. Without it being adjusted for the 'subst' variants the
displacement value is omitted resulting in a wrong shift count being applied.

This patch needs to be applied to older branches as well.

gcc/ChangeLog:

2019-07-01  Andreas Krebbel  <krebbel@linux.ibm.com>

	* config/s390/vector.md:

gcc/testsuite/ChangeLog:

2019-07-01  Andreas Krebbel  <krebbel@linux.ibm.com>

	* gcc.target/s390/vector/vec-shift-2.c: New test.

From-SVN: r272884