match: Fix `a != 0 ? a * b : 0` patterns for things that trap [PR116772]

match: Fix `a != 0 ? a * b : 0` patterns for things that trap [PR116772]

For generic, `a != 0 ? a * b : 0` would match where `b` would be an expression
which trap (in the case of the testcase, it was an integer division but it could be any).

This adds a new helper function, expr_no_side_effects_p which tests if there is no side effects
and the expression is not trapping which might be used in other locations.

Changes since v1:
* v2: Add move check to helper function instead of inlining it.

	PR middle-end/116772

gcc/ChangeLog:

	* generic-match-head.cc (expr_no_side_effects_p): New function
	* gimple-match-head.cc (expr_no_side_effects_p): New function
	* match.pd (`a != 0 ? a / b : 0`): Check expr_no_side_effects_p.
	(`a != 0 ? a * b : 0`, `a != 0 ? a & b : 0`): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.dg/torture/pr116772-1.c: New test.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>