[ObjC] Include the version checks in generated impl files.

There's always the chance someone will mix these, so play it safe and have checks in both.

PiperOrigin-RevId: 508114797

objectivec/GPBStruct.pbobjc.m

diff --git a/objectivec/GPBStruct.pbobjc.m b/objectivec/GPBStruct.pbobjc.m
index aff7078..7a53de3 100644
--- a/objectivec/GPBStruct.pbobjc.m
+++ b/objectivec/GPBStruct.pbobjc.m
@@ -5,6 +5,13 @@
 #import "GPBProtocolBuffers_RuntimeSupport.h"
 #import "GPBStruct.pbobjc.h"
 
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30007
+#error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
+#endif
+#if 30007 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
+#endif
+
 #import <stdatomic.h>
 
 // @@protoc_insertion_point(imports)