harmony-scoping: make assignment to 'const' a late error.

src/ia32/full-codegen-ia32.cc

Index: src/ia32/full-codegen-ia32.cc
diff --git a/src/ia32/full-codegen-ia32.cc b/src/ia32/full-codegen-ia32.cc
index 672b46bb2568859538118bc11e82d28c74f877d1..1ba409571534ee945cf8a3d16e972c61c5bcb1c4 100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -2575,7 +2575,6 @@ void FullCodeGenerator::EmitVariableAssignment(Variable* var,
     __ CallRuntime(Runtime::kThrowReferenceError, 1);
     __ bind(&assign);
     EmitStoreToStackLocalOrContextSlot(var, location);
-
   } else if (!var->is_const_mode() || op == Token::INIT_CONST) {
     if (var->IsLookupSlot()) {
       // Assignment to var.
@@ -2597,8 +2596,9 @@ void FullCodeGenerator::EmitVariableAssignment(Variable* var,
       }
       EmitStoreToStackLocalOrContextSlot(var, location);
     }
+  } else if (IsSignallingAssignmentToConst(var, op, strict_mode())) {
+    __ CallRuntime(Runtime::kThrowConstAssignError, 0);
   }
-  // Non-initializing assignments to consts are ignored.
 }