Move storage_class validation from wgsl to resolver

We don't want the WGSL parser to have to maintain type lookups.
If the WGSL language is updated to allow module-scope variables to be declared in any order, then the single-pass approach is going to fail horribly.

Instead do the check in the Resovler.
With this change, the AST nodes actually contain the correctly declared storage class.

Fix up the SPIR-V reader to generate StorageClass::kNone for handle types.
Fix all tests.

Bug: tint:724
Change-Id: I102e30c9bbef32de40e123c2676ea9a281dee74d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/50306
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: James Price <jrprice@google.com>

src/ast/intrinsic_texture_helper_test.cc

@@ -158,24 +158,23 @@ ast::Variable* TextureOverloadCase::buildTextureVariable(
       return b->Global("texture",
                        b->ty.sampled_texture(texture_dimension,
                                              buildResultVectorComponentType(b)),
-                       ast::StorageClass::kUniformConstant, nullptr, decos);
+                       ast::StorageClass::kNone, nullptr, decos);
 
     case ast::intrinsic::test::TextureKind::kDepth:
       return b->Global("texture", b->ty.depth_texture(texture_dimension),
-                       ast::StorageClass::kUniformConstant, nullptr, decos);
+                       ast::StorageClass::kNone, nullptr, decos);
 
     case ast::intrinsic::test::TextureKind::kMultisampled:
       return b->Global(
           "texture",
           b->ty.multisampled_texture(texture_dimension,
                                      buildResultVectorComponentType(b)),
-          ast::StorageClass::kUniformConstant, nullptr, decos);
+          ast::StorageClass::kNone, nullptr, decos);
 
     case ast::intrinsic::test::TextureKind::kStorage: {
       auto st = b->ty.storage_texture(texture_dimension, image_format);
       auto ac = b->ty.access(access_control, st);
-      return b->Global("texture", ac, ast::StorageClass::kUniformConstant,
-                       nullptr, decos);
+      return b->Global("texture", ac, ast::StorageClass::kNone, nullptr, decos);
     }
   }
 
@@ -190,7 +189,7 @@ ast::Variable* TextureOverloadCase::buildSamplerVariable(
       b->create<ast::BindingDecoration>(1),
   };
   return b->Global("sampler", b->ty.sampler(sampler_kind),
-                   ast::StorageClass::kUniformConstant, nullptr, decos);
+                   ast::StorageClass::kNone, nullptr, decos);
 }
 
 std::vector<TextureOverloadCase> TextureOverloadCase::ValidCases() {

src/ast/storage_class.cc

@@ -19,6 +19,10 @@ namespace ast {
 
 std::ostream& operator<<(std::ostream& out, StorageClass sc) {
   switch (sc) {
+    case StorageClass::kInvalid: {
+      out << "invalid";
+      break;
+    }
     case StorageClass::kNone: {
       out << "none";
       break;

src/ast/storage_class.h

@@ -22,7 +22,8 @@ namespace ast {
 
 /// Storage class of a given pointer.
 enum class StorageClass {
-  kNone = -1,
+  kInvalid = -1,
+  kNone,
   kInput,
   kOutput,
   kUniform,