[ObjC] Update some library internals to not pass syntax versions.

- With the new flags, the syntax isn't needed, so don't pass it.
- To keep library binary compatibility, rename the helpers since one
  "Internal" method was called from generated code. Keep a shim with
  the old signature to support those generated sources.
diff --git a/objectivec/GPBUtilities_PackagePrivate.h b/objectivec/GPBUtilities_PackagePrivate.h
index 1638a8c..280b6de 100644
--- a/objectivec/GPBUtilities_PackagePrivate.h
+++ b/objectivec/GPBUtilities_PackagePrivate.h
@@ -213,98 +213,79 @@
 #pragma clang diagnostic pop
 
 //%PDDM-DEFINE GPB_IVAR_SET_DECL(NAME, TYPE)
-//%void GPBSet##NAME##IvarWithFieldInternal(GPBMessage *self,
-//%            NAME$S                     GPBFieldDescriptor *field,
-//%            NAME$S                     TYPE value,
-//%            NAME$S                     GPBFileSyntax syntax);
+//%void GPBSet##NAME##IvarWithFieldPrivate(GPBMessage *self,
+//%            NAME$S                    GPBFieldDescriptor *field,
+//%            NAME$S                    TYPE value);
 //%PDDM-EXPAND GPB_IVAR_SET_DECL(Bool, BOOL)
 // This block of code is generated, do not edit it directly.
 // clang-format off
 
-void GPBSetBoolIvarWithFieldInternal(GPBMessage *self,
-                                     GPBFieldDescriptor *field,
-                                     BOOL value,
-                                     GPBFileSyntax syntax);
+void GPBSetBoolIvarWithFieldPrivate(GPBMessage *self,
+                                    GPBFieldDescriptor *field,
+                                    BOOL value);
 // clang-format on
 //%PDDM-EXPAND GPB_IVAR_SET_DECL(Int32, int32_t)
 // This block of code is generated, do not edit it directly.
 // clang-format off
 
-void GPBSetInt32IvarWithFieldInternal(GPBMessage *self,
-                                      GPBFieldDescriptor *field,
-                                      int32_t value,
-                                      GPBFileSyntax syntax);
+void GPBSetInt32IvarWithFieldPrivate(GPBMessage *self,
+                                     GPBFieldDescriptor *field,
+                                     int32_t value);
 // clang-format on
 //%PDDM-EXPAND GPB_IVAR_SET_DECL(UInt32, uint32_t)
 // This block of code is generated, do not edit it directly.
 // clang-format off
 
-void GPBSetUInt32IvarWithFieldInternal(GPBMessage *self,
-                                       GPBFieldDescriptor *field,
-                                       uint32_t value,
-                                       GPBFileSyntax syntax);
+void GPBSetUInt32IvarWithFieldPrivate(GPBMessage *self,
+                                      GPBFieldDescriptor *field,
+                                      uint32_t value);
 // clang-format on
 //%PDDM-EXPAND GPB_IVAR_SET_DECL(Int64, int64_t)
 // This block of code is generated, do not edit it directly.
 // clang-format off
 
-void GPBSetInt64IvarWithFieldInternal(GPBMessage *self,
-                                      GPBFieldDescriptor *field,
-                                      int64_t value,
-                                      GPBFileSyntax syntax);
+void GPBSetInt64IvarWithFieldPrivate(GPBMessage *self,
+                                     GPBFieldDescriptor *field,
+                                     int64_t value);
 // clang-format on
 //%PDDM-EXPAND GPB_IVAR_SET_DECL(UInt64, uint64_t)
 // This block of code is generated, do not edit it directly.
 // clang-format off
 
-void GPBSetUInt64IvarWithFieldInternal(GPBMessage *self,
-                                       GPBFieldDescriptor *field,
-                                       uint64_t value,
-                                       GPBFileSyntax syntax);
+void GPBSetUInt64IvarWithFieldPrivate(GPBMessage *self,
+                                      GPBFieldDescriptor *field,
+                                      uint64_t value);
 // clang-format on
 //%PDDM-EXPAND GPB_IVAR_SET_DECL(Float, float)
 // This block of code is generated, do not edit it directly.
 // clang-format off
 
-void GPBSetFloatIvarWithFieldInternal(GPBMessage *self,
-                                      GPBFieldDescriptor *field,
-                                      float value,
-                                      GPBFileSyntax syntax);
+void GPBSetFloatIvarWithFieldPrivate(GPBMessage *self,
+                                     GPBFieldDescriptor *field,
+                                     float value);
 // clang-format on
 //%PDDM-EXPAND GPB_IVAR_SET_DECL(Double, double)
 // This block of code is generated, do not edit it directly.
 // clang-format off
 
-void GPBSetDoubleIvarWithFieldInternal(GPBMessage *self,
-                                       GPBFieldDescriptor *field,
-                                       double value,
-                                       GPBFileSyntax syntax);
+void GPBSetDoubleIvarWithFieldPrivate(GPBMessage *self,
+                                      GPBFieldDescriptor *field,
+                                      double value);
 // clang-format on
-//%PDDM-EXPAND GPB_IVAR_SET_DECL(Enum, int32_t)
-// This block of code is generated, do not edit it directly.
-// clang-format off
+//%PDDM-EXPAND-END (7 expansions)
 
-void GPBSetEnumIvarWithFieldInternal(GPBMessage *self,
-                                     GPBFieldDescriptor *field,
-                                     int32_t value,
-                                     GPBFileSyntax syntax);
-// clang-format on
-//%PDDM-EXPAND-END (8 expansions)
-
-int32_t GPBGetEnumIvarWithFieldInternal(GPBMessage *self,
-                                        GPBFieldDescriptor *field,
-                                        GPBFileSyntax syntax);
+void GPBSetEnumIvarWithFieldPrivate(GPBMessage *self,
+                                    GPBFieldDescriptor *field,
+                                    int32_t value);
 
 id GPBGetObjectIvarWithField(GPBMessage *self, GPBFieldDescriptor *field);
 
-void GPBSetObjectIvarWithFieldInternal(GPBMessage *self,
-                                       GPBFieldDescriptor *field, id value,
-                                       GPBFileSyntax syntax);
-void GPBSetRetainedObjectIvarWithFieldInternal(GPBMessage *self,
-                                               GPBFieldDescriptor *field,
-                                               id __attribute__((ns_consumed))
-                                               value,
-                                               GPBFileSyntax syntax);
+void GPBSetObjectIvarWithFieldPrivate(GPBMessage *self,
+                                      GPBFieldDescriptor *field, id value);
+void GPBSetRetainedObjectIvarWithFieldPrivate(GPBMessage *self,
+                                              GPBFieldDescriptor *field,
+                                              id __attribute__((ns_consumed))
+                                              value);
 
 // GPBGetObjectIvarWithField will automatically create the field (message) if
 // it doesn't exist. GPBGetObjectIvarWithFieldNoAutocreate will return nil.
@@ -331,6 +312,13 @@
 NSString *GPBDecodeTextFormatName(const uint8_t *decodeData, int32_t key,
                                   NSString *inputString);
 
+
+// Shim from the older generated code into the runtime.
+void GPBSetInt32IvarWithFieldInternal(GPBMessage *self,
+                                      GPBFieldDescriptor *field,
+                                      int32_t value,
+                                      GPBFileSyntax syntax);
+
 // A series of selectors that are used solely to get @encoding values
 // for them by the dynamic protobuf runtime code. See
 // GPBMessageEncodingForSelector for details. GPBRootObject conforms to