ipa-sra: Do not remove statements necessary because of non-call EH (PR 95113)

ipa-sra: Do not remove statements necessary because of non-call EH (PR 95113)

PR 95113 revealed that when reasoning about which parameters are dead,
IPA-SRA does not perform the same check related to non-call exceptions
as tree DCE.  It most certainly should and so this patch moves the
condition used in tree-ssa-dce.c into a separate predicate (in
tree-eh.c) and uses it from both places.

gcc/ChangeLog:

2020-05-27  Martin Jambor  <mjambor@suse.cz>

	PR ipa/95113
	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Move non-call
	exceptions check to...
	* tree-eh.c (stmt_unremovable_because_of_non_call_eh_p): ...this
	new function.
	* tree-eh.h (stmt_unremovable_because_of_non_call_eh_p): Declare it.
	* ipa-sra.c (isra_track_scalar_value_uses): Use it.  New parameter
	fun.

gcc/testsuite/ChangeLog:

2020-05-27  Martin Jambor  <mjambor@suse.cz>

	PR ipa/95113
	* gcc.dg/ipa/pr95113.c: New test.