[ObjC] Mark some of the old apis as deprecated

The old generated code suppressed warnings broadly to support protobuf
deprecations like this showing to users, but the previous commit does
provide a debug log statement for the usages.

PiperOrigin-RevId: 670581568

objectivec/GPBDescriptor_PackagePrivate.h

@@ -227,8 +227,12 @@ typedef NS_OPTIONS(uint32_t, GPBDescriptorInitializationFlags) {
                                   flags:(GPBDescriptorInitializationFlags)flags
     __attribute__((deprecated("Please use a newer version of protoc to regenerate your sources. "
                               "Support for this version will go away in the future.")));
-- (void)setupContainingMessageClassName:(const char *)msgClassName;
+- (void)setupContainingMessageClassName:(const char *)msgClassName
-- (void)setupMessageClassNameSuffix:(NSString *)suffix;
+    __attribute__((deprecated("Please use a newer version of protoc to regenerate your sources. "
+                              "Support for this version will go away in the future.")));
+- (void)setupMessageClassNameSuffix:(NSString *)suffix
+    __attribute__((deprecated("Please use a newer version of protoc to regenerate your sources. "
+                              "Support for this version will go away in the future.")));
 
 @end
 

objectivec/GPBUtilities_PackagePrivate.h

@@ -51,8 +51,12 @@ void GPBRuntimeMatchFailure(void);
 
 // Legacy version of the checks, remove when GOOGLE_PROTOBUF_OBJC_GEN_VERSION
 // goes away (see more info in GPBBootstrap.h).
-void GPBCheckRuntimeVersionInternal(int32_t version);
+void GPBCheckRuntimeVersionInternal(int32_t version)
-GPB_INLINE void GPBDebugCheckRuntimeVersion(void) {
+    __attribute__((deprecated("Please use a newer version of protoc to regenerate your sources. "
+                              "Support for this version will go away in the future.")));
+__attribute__((deprecated("Please use a newer version of protoc to regenerate your sources. "
+                          "Support for this version will go away in the future."))) GPB_INLINE void
+GPBDebugCheckRuntimeVersion(void) {
 #if defined(DEBUG) && DEBUG
   GPBCheckRuntimeVersionInternal(GOOGLE_PROTOBUF_OBJC_GEN_VERSION);
 #endif