[torque] fix SpecializationRequester to not run into temporary namespaces

Bug: v8:7793
Change-Id: Ibf045274ae48bd58f8c99361f02e51860b1a4150
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1997443
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Auto-Submit: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65777}

src/torque/declarable.cc

@@ -67,6 +67,16 @@ std::ostream& operator<<(std::ostream& os, const GenericCallable& g) {
   return os;
 }
 
+SpecializationRequester::SpecializationRequester(SourcePosition position,
+                                                 Scope* scope, std::string name)
+    : position(position), name(std::move(name)) {
+  // Skip scopes that are not related to template specializations, they might be
+  // stack-allocated and not live for long enough.
+  while (scope && scope->GetSpecializationRequester().IsNone())
+    scope = scope->ParentScope();
+  this->scope = scope;
+}
+
 base::Optional<std::string> TypeConstraint::IsViolated(const Type* type) const {
   if (upper_bound && !type->IsSubtypeOf(*upper_bound)) {
     return {ToString("expected ", *type, " to be a subtype of ", *upper_bound)};

src/torque/declarable.h

@@ -153,6 +153,8 @@ struct SpecializationRequester {
     return position == SourcePosition::Invalid() && scope == nullptr &&
            name == "";
   }
+  SpecializationRequester(SourcePosition position, Scope* scope,
+                          std::string name);
 };
 
 class Scope : public Declarable {