Fix PR tree-optimization/103228 and 103228: folding of (type) X op CST where type...

Fix PR tree-optimization/103228 and 103228: folding of (type) X op CST where type is a nop convert

Currently we fold (type) X op CST into (type) (X op ((type-x) CST)) when the conversion widens
but not when the conversion is a nop. For the same reason why we move the widening conversion
(the possibility of removing an extra conversion), we should do the same if the conversion is a
nop.

Committed as approved with the comment change.

	PR tree-optimization/103228
	PR tree-optimization/55177

gcc/ChangeLog:

	* match.pd ((type) X bitop CST): Also do this
	transformation for nop conversions.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr103228-1.c: New test.
	* gcc.dg/tree-ssa/pr55177-1.c: New test.