Add a new method that adds the AttributeSet at the given index. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173109 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index fe6366d..420b2e8 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -691,14 +691,9 @@
   return false;
 }
 
-AttributeSet AttributeSet::addRetAttributes(LLVMContext &C,
-                                            AttributeSet Attrs) const {
-  return addAttr(C, ReturnIndex, Attrs.getAttributes(ReturnIndex));
-}
-
-AttributeSet AttributeSet::addFnAttributes(LLVMContext &C,
-                                           AttributeSet Attrs) const {
-  return addAttr(C, FunctionIndex, Attrs.getAttributes(FunctionIndex));
+AttributeSet AttributeSet::addAttributes(LLVMContext &C, unsigned Idx,
+                                         AttributeSet Attrs) const {
+  return addAttr(C, Idx, Attrs.getAttributes(Idx));
 }
 
 AttributeSet AttributeSet::addAttr(LLVMContext &C, unsigned Idx,