PODness and Type Traits

Make C++ classes track the POD property (C++ [class]p4)
Track the existence of a copy assignment operator.
Implicitly declare the copy assignment operator if none is provided.
Implement most of the parsing job for the G++ type traits extension.
Fully implement the low-hanging fruit of the type traits:
__is_pod: Whether a type is a POD.
__is_class: Whether a type is a (non-union) class.
__is_union: Whether a type is a union.
__is_enum: Whether a type is an enum.
__is_polymorphic: Whether a type is polymorphic (C++ [class.virtual]p1).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61746 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index d3f373f..e35c06d 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -918,6 +918,14 @@
                                                       SourceLocation EqualLoc,
                                                       ExprTy *AssignExprVal);
 
+  /// ActOnUnaryTypeTrait - Parsed one of the unary type trait support
+  /// pseudo-functions.
+  virtual OwningExprResult ActOnUnaryTypeTrait(UnaryTypeTrait OTT,
+                                               SourceLocation KWLoc,
+                                               SourceLocation LParen,
+                                               TypeTy *Ty,
+                                               SourceLocation RParen);
+
   /// ActOnCXXGlobalScopeSpecifier - Return the object that represents the
   /// global scope ('::').
   virtual CXXScopeTy *ActOnCXXGlobalScopeSpecifier(Scope *S,