[PATCH] Implement DR21

[David Majnemer]

This patch implements CWG DR21 [*]

Interestingly, we properly handled default template arguments on friend
class members but not on just friend classes:
struct A {
  template <class T1> void foo();
};
class B {
  template <class T1 = int> friend void A::foo();
};

[*] http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#21

-- 
David Majnemer
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20130622/b5893a67/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dr21.diff
Type: application/octet-stream
Size: 3439 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20130622/b5893a67/attachment.obj>