[IR] Upgrade comment token in objc retain release marker

Older compiler issued '#' instead of ';'

llvm-svn: 329248

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -4788,6 +4788,9 @@ Error BitcodeReader::materializeModule() {
   UpgradeDebugInfo(*TheModule);
 
   UpgradeModuleFlags(*TheModule);
+
+  UpgradeRetainReleaseMarker(*TheModule);
+
   return Error::success();
 }