Add some Function method definitions accidentally removed

In cc327bd.

Author: aeubanks

llvm/lib/IR/Function.cpp

@@ -533,6 +533,14 @@ void Function::addAttribute(unsigned i, Attribute Attr) {
   AttributeSets = AttributeSets.addAttribute(getContext(), i, Attr);
 }
 
+void Function::addAttribute(unsigned i, Attribute::AttrKind Attr) {
+  AttributeSets = AttributeSets.addAttribute(getContext(), i, Attr);
+}
+
+void Function::addAttributes(unsigned i, const AttrBuilder &Attrs) {
+  AttributeSets = AttributeSets.addAttributes(getContext(), i, Attrs);
+}
+
 void Function::addFnAttr(Attribute::AttrKind Kind) {
   AttributeSets = AttributeSets.addFnAttribute(getContext(), Kind);
 }