[interpreter] Add a fast path for dynamic local load

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 27158cd8bfa6d281bd420b119d0805561ca2b84e..43ab0e3abe0e0103ac6fde664fcd89138360f67c 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -1967,7 +1967,19 @@ void BytecodeGenerator::VisitVariableLoad(Variable* variable,
       break;
     }
     case VariableLocation::LOOKUP: {
-      builder()->LoadLookupSlot(variable->name(), typeof_mode);
+      switch (variable->mode()) {
+        case DYNAMIC_LOCAL: {
+          Variable* local_variable = variable->local_if_not_shadowed();
+          int depth =
+              execution_context()->ContextChainDepth(local_variable->scope());
+          builder()->LoadLookupContextSlot(variable->name(), typeof_mode,
+                                           local_variable->index(), depth);
+          BuildHoleCheckForVariableLoad(variable);
+          break;
+        }
+        default:
+          builder()->LoadLookupSlot(variable->name(), typeof_mode);
+      }
       break;
     }
     case VariableLocation::MODULE: {