[torque] Add lint rules for redundant clauses

This change adds two simple lint rules to prevent including 'generates'
or 'constexpr' clauses in cases where they have no impact on behavior.

Bug: v8:7793
Change-Id: Ib1d8fde39ca26735ff9cb7892f01e464619c2090
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2590515Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#71831}

src/builtins/constructor.tq

@@ -17,7 +17,7 @@ namespace constructor {
 
 extern builtin FastNewObject(Context, JSFunction, JSReceiver): JSObject;
 
-extern enum AllocationSiteMode constexpr 'AllocationSiteMode' {
+extern enum AllocationSiteMode {
   DONT_TRACK_ALLOCATION_SITE,
   TRACK_ALLOCATION_SITE
 }

src/objects/js-array.tq

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-extern enum IterationKind extends uint31
-constexpr 'IterationKind' { kKeys, kValues, kEntries }
+extern enum IterationKind extends uint31 { kKeys, kValues, kEntries }
 
 extern class JSArrayIterator extends JSObject {
   iterated_object: JSReceiver;

src/torque/torque-parser.cc

@@ -1281,6 +1281,9 @@ base::Optional<ParseResult> MakeEnumDeclaration(
     NamingConventionError("Type", name, "UpperCamelCase");
   }
 
+  if (constexpr_generates_opt && *constexpr_generates_opt == name) {
+    Lint("Unnecessary 'constexpr' clause for enum ", name);
+  }
   auto constexpr_generates =
       constexpr_generates_opt ? *constexpr_generates_opt : name;
   const bool generate_nonconstexpr = base_type_expression.has_value();

src/torque/type-visitor.cc

@@ -300,7 +300,12 @@ const ClassType* TypeVisitor::ComputeType(
   if (flags & ClassFlag::kExtern) {
     if (decl->generates) {
       bool enforce_tnode_type = true;
-      generates = ComputeGeneratesType(decl->generates, enforce_tnode_type);
+      std::string explicit_generates =
+          ComputeGeneratesType(decl->generates, enforce_tnode_type);
+      if (explicit_generates == generates) {
+        Lint("Unnecessary 'generates' clause for class ", decl->name->value);
+      }
+      generates = explicit_generates;
     }
     if (flags & ClassFlag::kExport) {
       Error("cannot export a class that is marked extern");