Added a new attribute, objc_root_class, which informs the compiler when a root class is intentionally declared.
The warning this inhibits, -Wobjc-root-class, is opt-in for now. However, all clang unit tests that would trigger
the warning have been updated to use -Wno-objc-root-class. <rdar://problem/7446698>


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154187 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseObjc.cpp b/lib/Parse/ParseObjc.cpp
index c664c64..11417fb 100644
--- a/lib/Parse/ParseObjc.cpp
+++ b/lib/Parse/ParseObjc.cpp
@@ -161,6 +161,7 @@
 ///     __attribute__((deprecated))
 ///     __attribute__((unavailable))
 ///     __attribute__((objc_exception)) - used by NSException on 64-bit
+///     __attribute__((objc_root_class))
 ///
 Decl *Parser::ParseObjCAtInterfaceDeclaration(SourceLocation AtLoc,
                                               ParsedAttributes &attrs) {