pr45260 Don't generate prefetch if the address of base could not be taken.

	* tree-flow.h (may_be_nonaddressable_p): New definition. Make the
	existing static function global.

	*tree-ssa-loop-ivopts.c (may_be_nonaddressable_p): This function
	is changed to global.

	*tree-ssa-loop-prefetch.c (gather_memory_references_ref): Call
	may_be_nonaddressable_p on base, and don't collect this reference
	if the address of the base could not be taken.

From-SVN: r163475