[torque] fix bugs found by using implicit params in generics at scale

Bug: v8:7793
Change-Id: I2d5154eabd549c0518ca41dae6ef7bd047f3e1ef
Reviewed-on: https://chromium-review.googlesource.com/c/1348072Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57772}

src/torque/declarable.cc

@@ -71,9 +71,10 @@ base::Optional<const Type*> Generic::InferTypeArgument(
   const std::string type_name = declaration()->generic_parameters[i];
   const std::vector<TypeExpression*>& parameters =
       declaration()->callable->signature->parameters.types;
-  for (size_t i = 0; i < arguments.size() && i < parameters.size(); ++i) {
+  size_t j = declaration()->callable->signature->parameters.implicit_count;
+  for (size_t i = 0; i < arguments.size() && j < parameters.size(); ++i, ++j) {
     BasicTypeExpression* basic =
-        BasicTypeExpression::DynamicCast(parameters[i]);
+        BasicTypeExpression::DynamicCast(parameters[j]);
     if (basic && basic->namespace_qualification.empty() &&
         !basic->is_constexpr && basic->name == type_name) {
       return arguments[i];

src/torque/types.cc

@@ -261,7 +261,7 @@ bool Signature::HasSameTypesAs(const Signature& other,
     compare_types = GetExplicitTypes();
     other_compare_types = other.GetExplicitTypes();
   }
-  if (!(compare_types == other.parameter_types.types &&
+  if (!(compare_types == other_compare_types &&
         parameter_types.var_args == other.parameter_types.var_args &&
         return_type == other.return_type)) {
     return false;