Add -Wextra-semi -Wundefined-func-template to the default CXXFLAGS

And fix the resulting compilation errors.

Change-Id: I16f679836a0cf2a3ff5dfcf6f6b67bfbfe4cdbd7
Refs: #4248
diff --git a/src/mgmt/nfd/rib-entry.cpp b/src/mgmt/nfd/rib-entry.cpp
index 475af15..c4c2d82 100644
--- a/src/mgmt/nfd/rib-entry.cpp
+++ b/src/mgmt/nfd/rib-entry.cpp
@@ -118,11 +118,7 @@
   return totalLength;
 }
 
-template size_t
-Route::wireEncode<encoding::EncoderTag>(EncodingImpl<encoding::EncoderTag>& block) const;
-
-template size_t
-Route::wireEncode<encoding::EstimatorTag>(EncodingImpl<encoding::EstimatorTag>& block) const;
+NDN_CXX_DEFINE_WIRE_ENCODE_INSTANTIATIONS(Route);
 
 const Block&
 Route::wireEncode() const
@@ -269,11 +265,7 @@
   return totalLength;
 }
 
-template size_t
-RibEntry::wireEncode<encoding::EncoderTag>(EncodingImpl<encoding::EncoderTag>& block) const;
-
-template size_t
-RibEntry::wireEncode<encoding::EstimatorTag>(EncodingImpl<encoding::EstimatorTag>& block) const;
+NDN_CXX_DEFINE_WIRE_ENCODE_INSTANTIATIONS(RibEntry);
 
 const Block&
 RibEntry::wireEncode() const