[llvm] [IntrinsicEmitter] Make AttributesMap PackedID type-adaptive (PR #158383)

[Rahul Joshi via llvm-commits]

================
@@ -776,19 +790,16 @@ AttributeList Intrinsic::getAttributes(LLVMContext &C, ID id,
   return AttributeList::get(C, ArrayRef(AS, NumAttrs));
 }
 
-AttributeSet Intrinsic::getFnAttributes(LLVMContext &C, ID id) {
+AttributeSet Intrinsic::getFnAttributes(LLVMContext &C, ID id) {{
   if (id == 0)
     return AttributeSet();
-  uint16_t PackedID = IntrinsicsToAttributesMap[id - 1];
-  uint16_t FnAttrID = PackedID >> ({});
+  auto [FnAttrID, ArgAttrID] = unpackID(IntrinsicsToAttributesMap[id - 1]);
----------------
jurahul wrote:

```
auto [FnAttrID, _] = ...
```

https://github.com/llvm/llvm-project/pull/158383