ast: Remove helpers from ast::Type

These are legacy methods that were written before the semantic type nodes.

These methods do not consider aliases, and any use of these is likely to be broken for aliases.

Fix up uses of these methods to use the semantic types instead.

Change-Id: Ia66749b279eddff655d3d755fef54a6263643e69
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/66601
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

src/resolver/intrinsic_test.cc

@@ -244,7 +244,7 @@ class ResolverIntrinsicTest_TextureOperation
   void add_call_param(std::string name,
                       const ast::Type* type,
                       ast::ExpressionList* call_params) {
-    if (type->UnwrapAll()->is_handle()) {
+    if (type->IsAnyOf<ast::Texture, ast::Sampler>()) {
       Global(name, type,
              ast::DecorationList{
                  create<ast::BindingDecoration>(0),