[gdb/testsuite] Add KFAIL for missing support of reverse-debugging of vmovd

[gdb/testsuite] Add KFAIL for missing support of reverse-debugging of vmovd

On my openSUSE Leap 15.1 system I run into:
...
(gdb) PASS: gdb.reverse/step-precsave.exp: turn on process record
break 76^M
Breakpoint 2 at 0x400654: file step-reverse.c, line 76.^M
(gdb) PASS: gdb.reverse/step-precsave.exp: breakpoint at end of main
continue^M
Continuing.^M
Process record does not support instruction 0xc5 at address 0x7ffff783fc70.^M
Process record: failed to record execution log.^M
^M
Program stopped.^M
0x00007ffff783fc70 in __memset_avx2_unaligned_erms () from /lib64/libc.so.6^M
(gdb) FAIL: gdb.reverse/step-precsave.exp: run to end of main
...

The problem is that the vmovd instruction is not supported in
reverse-debugging (PR record/23188).

Add a KFAIL for this PR.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2019-09-27  Tom de Vries  <tdevries@suse.de>

	PR record/23188
	* gdb.reverse/step-precsave.exp: Add kfail for PR record/23188.