MATCH: Add some more value_replacement simplifications to match

MATCH: Add some more value_replacement simplifications to match

This moves a few more value_replacements simplifications to match.
/* a == 1 ? b : a * b -> a * b */
/* a == 1 ? b : b / a  -> b / a */
/* a == -1 ? b : a & b -> a & b */

Also adds a testcase to show can we catch these where value_replacement would not
(but other passes would).

Bootstrapped and tested on x86_64-linux-gnu with no regressions.

gcc/ChangeLog:

	* match.pd (`a == 1 ? b : a OP b`): New pattern.
	(`a == -1 ? b : a & b`): New pattern.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/phi-opt-value-4.c: New test.