[llvm] Add the 'initializes' attribute langref and support (PR #84803)

[Arthur Eubanks via llvm-commits]

================
@@ -124,6 +133,16 @@ class AttributeImpl : public FoldingSetNode {
     CR.getLower().Profile(ID);
     CR.getUpper().Profile(ID);
   }
+
+  static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
+                      const ConstantRangeList &CRL) {
+    ID.AddInteger(Kind);
+    ID.AddInteger(CRL.size());
----------------
aeubanks wrote:

should also add bit width here now

https://github.com/llvm/llvm-project/pull/84803