Fix PR 102908: wrongly removing null pointer loads

Fix PR 102908: wrongly removing null pointer loads

Just like PR 100382, here we have a DCE removing a
null pointer load which is needed still.
In this case, execute_fixup_cfg removes a store (correctly)
and then removes the null load (incorrectly) due to
not checking stmt_unremovable_because_of_non_call_eh_p.
This patch adds the check in the similar way as the patch
to fix PR 100382 did.

gcc/ChangeLog:

	* tree-ssa-dce.c (simple_dce_from_worklist):
	Check stmt_unremovable_because_of_non_call_eh_p also
	before removing the statement.