Remove Attr::isMerged; it is not used any more and redundant with
InheritableAttr

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124298 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/Attr.h b/include/clang/AST/Attr.h
index d8f0979..a6d23e5 100644
--- a/include/clang/AST/Attr.h
+++ b/include/clang/AST/Attr.h
@@ -89,10 +89,6 @@
 
 public:
 
-  /// \brief Whether this attribute should be merged to new
-  /// declarations.
-  virtual bool isMerged() const { return true; }
-
   attr::Kind getKind() const {
     return static_cast<attr::Kind>(AttrKind);
   }