Handle VIEW_CONVERT_EXPR for non-floats.

Handle VIEW_CONVERT_EXPR for non-floats.

Handle VIEW_CONVERT_EXPR for ranges as if it were a cast.

	PR tree-optimization/91191
	gcc/
	* gimple-range-op.cc (gimple_range_op_handler): Descend one
	operand lower for a VIEW_CONVERT_EXPR.
	* range-op-mixed.h (class operator_view): New.
	* range-op.cc (range_op_table): Add VIEW_CONVERT_EXPR case.
	(operator_view::fold_range): New.
	(operator_view::op1_range): New.
	(operator_view::update_bitmask): New.

	gcc/testsuite/
	* gcc.dg/pr91191.c: New.