Update serialization codes.

Author: bgogul

utils/gyb_syntax_support/NodeSerializationCodes.py

@@ -233,17 +233,13 @@
     'PoundAssertStmt': 229,
     'SomeType': 230,
     'CustomAttribute': 231,
-    'GenericRequirement': 232,
-    'LayoutRequirement': 233,
-    'LayoutConstraint': 234,
-    'OpaqueReturnTypeOfAttributeArguments': 235,
-    'DifferentiableAttributeArguments': 236,
-    'DifferentiationParamsClause': 237,
-    'DifferentiationParams': 238,
-    'DifferentiationParamList': 239,
-    'DifferentiationParam': 240,
-    'DifferentiableAttributeFuncSpecifier': 241,
-    'FunctionDeclName': 242,
+    'DifferentiableAttributeArguments': 232,
+    'DifferentiationParamsClause': 233,
+    'DifferentiationParams': 234,
+    'DifferentiationParamList': 235,
+    'DifferentiationParam': 236,
+    'DifferentiableAttributeFuncSpecifier': 237,
+    'FunctionDeclName': 238,
 }