[cxx2a] Fix warning triggered by r343285

llvm-svn: 343369
GitOrigin-RevId: 0509070811a84fc2c69ac4b38d84e21935019420
diff --git a/clang-doc/BitcodeWriter.h b/clang-doc/BitcodeWriter.h
index 2ff46c6..12a31ea 100644
--- a/clang-doc/BitcodeWriter.h
+++ b/clang-doc/BitcodeWriter.h
@@ -169,7 +169,6 @@
       Stream.EnterSubblock(ID, BitCodeConstants::SubblockIDSize);
     }
 
-    StreamSubBlockGuard() = default;
     StreamSubBlockGuard(const StreamSubBlockGuard &) = delete;
     StreamSubBlockGuard &operator=(const StreamSubBlockGuard &) = delete;