[binutils-gdb] Fix cached_frame allocation in py-unwind

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 16892a0323ce6cf41ca80e384dfba12524247902 ***

Author: Alan Hayward <alan.hayward@arm.com>
Branch: master
Commit: 16892a0323ce6cf41ca80e384dfba12524247902

Fix cached_frame allocation in py-unwind

gdb/
	* python/py-unwind.c (pyuw_sniffer): Allocate space for
	registers.