testsuite patch: Skip py-unwind.exp on x86_64 -m32

testsuite patch: Skip py-unwind.exp on x86_64 -m32

(gdb) source /home/jkratoch/redhat/gdb-clean/gdb/testsuite/outputs/gdb.python/py-unwind/py-unwind.py^M
Python script imported^M
Python Exception <type 'exceptions.ValueError'> Bad register: ^M
(gdb) FAIL: gdb.python/py-unwind.exp: import python scripts

class TestUnwinder(Unwinder):
    AMD64_RBP = 6
    AMD64_RSP = 7
    AMD64_RIP = 16

On Tue, 19 Jul 2016 12:06:09 +0200, Yao Qi wrote:
py-unwind.exp does nothing on arch specific thing, so py-unwind.exp shouldn't
be aware of the arch difference, but py-unwind.py should.

On Tue, 19 Jul 2016 20:04:33 +0200, Pedro Alves wrote:
How about we handle this in the .exp file for now and leave something
more complicated for when the test is first ported to some other
arch.  WDYT?

gdb/testsuite/ChangeLog
2016-07-20  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.python/py-unwind.exp: Test also ![is_lp64_target].