tree-scalar-evolution.c (follow_ssa_edge_expr): Turn into CASE_CONVERT.

	* tree-scalar-evolution.c (follow_ssa_edge_expr) <NOP_EXPR>: Turn
	into CASE_CONVERT.
	<PLUS_EXPR>: Strip useless type conversions instead of type nops.
	Propagate the type of the first operand.
	<ASSERT_EXPR>: Simplify.
	(follow_ssa_edge_in_rhs): Use gimple_expr_type to get the type.
	Rewrite using the RHS code as discriminant.
	<NOP_EXPR>: Turn into CASE_CONVERT.
	<PLUS_EXPR>: Propagate the type of the first operand.

From-SVN: r147716