re PR tree-optimization/19828 (LIM is pulling out a pure function even though there is something which can modify global memory)

	PR tree-optimization/19828
	* tree-ssa-loop-im.c: Add a TODO comment.
	(movement_possibility): Return MOVE_PRESERVE_EXECUTION for calls
	without side-effects.

	* gcc.dg/tree-ssa/loop-7.c: New test.
	* gcc.c-torture/execute/20050218-1.c: New test.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r95275