Rename AttributeSet to AttributeList

Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
diff --git a/llvm/unittests/IR/VerifierTest.cpp b/llvm/unittests/IR/VerifierTest.cpp
index ad6940a..188509a 100644
--- a/llvm/unittests/IR/VerifierTest.cpp
+++ b/llvm/unittests/IR/VerifierTest.cpp
@@ -52,9 +52,9 @@
   Module M("M", C);
   FunctionType *FTy = FunctionType::get(Type::getInt32Ty(C), /*isVarArg=*/false);
   Function *F = cast<Function>(M.getOrInsertFunction("foo", FTy));
-  AttributeSet AS = F->getAttributes();
-  F->setAttributes(AS.addAttribute(C, AttributeSet::ReturnIndex,
-                                   Attribute::UWTable));
+  AttributeList AS = F->getAttributes();
+  F->setAttributes(
+      AS.addAttribute(C, AttributeList::ReturnIndex, Attribute::UWTable));
 
   std::string Error;
   raw_string_ostream ErrorOS(Error);