re PR tree-optimization/82052 (ICE with "-O3 -m32" on x86_64-linux-gnu (internal compiler error: in pop_to_marker, at tree-ssa-scopedtables.c:71))

	PR tree-optimization/82052
	* tree-ssa-scopedtables.c (avail_exprs_stack::lookup_avail_expr):
	Always initialize the returned slot after a hash table miss
	when INSERT is true.

	PR tree-optimization/82052
	* gcc.c-torture/compile/pr82052.c: New test.

From-SVN: r251600