Add -fobjc-default-synthesized-properties flag
to allow us to explicitly control whether or
not Objective-C properties are default synthesized.
Currently this feature only works when using
the -fobjc-non-fragile-abi2 flag (so there is
no functionality change), but we can now turn
off this feature without turning off all the features
coupled with -fobjc-non-fragile-abi2.

llvm-svn: 122519
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index bf07c52..8c0fb42 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -860,6 +860,8 @@
                                                  // modern abi enabled.
   Record.push_back(LangOpts.ObjCNonFragileABI2); // Objective-C enhanced
                                                  // modern abi enabled.
+  Record.push_back(LangOpts.ObjCDefaultSynthProperties); // Objective-C auto-synthesized
+                                                      // properties enabled.
   Record.push_back(LangOpts.NoConstantCFStrings); // non cfstring generation enabled..
 
   Record.push_back(LangOpts.PascalStrings);  // Allow Pascal strings