src/jdk/nashorn/internal/codegen/CodeGenerator.java

*** 1449,1459 ****
              final String       key          = propertyNode.getKeyName();
              final Symbol       symbol       = value == null ? null : propertyNode.getKey().getSymbol();
  
              if (value == null) {
                  hasGettersSetters = true;
!             } else if (key.equals(ScriptObject.PROTO_PROPERTY_NAME)) {
                  protoNode = value;
                  continue;
              }
  
              keys.add(key);
--- 1449,1462 ----
              final String       key          = propertyNode.getKeyName();
              final Symbol       symbol       = value == null ? null : propertyNode.getKey().getSymbol();
  
              if (value == null) {
                  hasGettersSetters = true;
!             } else if (propertyNode.getKey() instanceof IdentNode &&
!                        key.equals(ScriptObject.PROTO_PROPERTY_NAME)) {
!                 // ES6 draft compliant __proto__ inside object literal
!                 // Identifier key and name is __proto__
                  protoNode = value;
                  continue;
              }
  
              keys.add(key);