[ObjC] Generation changes around proto3 optional.
- Bump the version marker in the generated code.
- Set the flag to say clear on zero is known.
- Set clear on zero for proto3 optional fields that aren't tagged as optional.
- Also tweak the call from some C generated code to use different apis with
better validation.
- Mark the ObjC generator as supporting the proto3 optional feature.
- Regenerate the WKTs to get the new flags.
diff --git a/objectivec/GPBAny.pbobjc.h b/objectivec/GPBAny.pbobjc.h
index 233cc27..288d552 100644
--- a/objectivec/GPBAny.pbobjc.h
+++ b/objectivec/GPBAny.pbobjc.h
@@ -17,10 +17,10 @@
#import "GPBRootObject.h"
#endif
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
#error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
#endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < 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
