re PR c++/53261 (ICE in tree_strip_nop_conversions)

2012-05-09  Manuel López-Ibáñez  <manu@gcc.gnu.org>

	PR c++/53261
c-family/
	* c-common.c (warn_logical_operator): Check that argument of
	integer_zerop is not NULL.

From-SVN: r187300