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

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

Normally the gdb.reverse/*.exp test-cases pass on my system (apart from the
record/23188 KFAIL for gdb.reverse/step-precsave.exp).  But when specifying
GLIBC_TUNABLES=glibc.tune.hwcaps=-XSAVEC_Usable to force glibc to use
_dl_runtime_resolve_xsave instead of _dl_runtime_resolve_xsavec, we run into
1054 FAILs like this:
...
(gdb) PASS: gdb.reverse/sigall-reverse.exp: b gen_HUP
continue^M
Continuing.^M
Process record does not support instruction 0xfae64 at address \
  0x7ffff7ded958.^M
Process record: failed to record execution log.^M
^M
Program stopped.^M
0x00007ffff7ded958 in _dl_runtime_resolve_xsave () from \
  /lib64/ld-linux-x86-64.so.2^M
(gdb) FAIL: gdb.reverse/sigall-reverse.exp: get signal ABRT
...

The problem is that the xsave instruction is not supported in
reverse-debugging (PR record/25038).

Add KFAILs for this PR.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2019-10-13  Tom de Vries  <tdevries@suse.de>

	PR record/25038
	* gdb.reverse/sigall-precsave.exp: Add PR record/25038 KFAIL.
	* gdb.reverse/sigall-reverse.exp: Same.
	* gdb.reverse/solib-precsave.exp: Same.
	* gdb.reverse/solib-reverse.exp: Same.
	* gdb.reverse/step-precsave.exp: Same.
	* gdb.reverse/until-precsave.exp: Same.
	* gdb.reverse/until-reverse.exp: Same.
	* lib/gdb.exp (gdb_continue_to_breakpoint): Same.