Objective-C Class Properties: Autoupgrade "Class Properties" module flag.

When we have "Image Info Version" module flag but don't have "Class Properties"
module flag, set "Class Properties" module flag to 0, so we can correctly emit
errors when one module has the flag set and another module does not.

rdar://26469641

llvm-svn: 270791

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -5634,6 +5634,8 @@ std::error_code BitcodeReader::materializeModule() {
   UpgradedIntrinsics.clear();
 
   UpgradeDebugInfo(*TheModule);
+
+  UpgradeModuleFlags(*TheModule);
   return std::error_code();
 }