Rollup merge of #58511 - oli-obk:const_to_op, r=RalfJung

Const to op simplification

r? @RalfJung

alternative to https://github.com/rust-lang/rust/pull/58486

src/librustc_codegen_llvm/consts.rs

@@ -71,7 +71,7 @@ pub fn codegen_static_initializer(
     let static_ = cx.tcx.const_eval(param_env.and(cid))?;
 
     let alloc = match static_.val {
-        ConstValue::ByRef(_, alloc, n) if n.bytes() == 0 => alloc,
+        ConstValue::ByRef(ptr, alloc) if ptr.offset.bytes() == 0 => alloc,
         _ => bug!("static const eval returned {:#?}", static_),
     };
     Ok((const_alloc_to_llvm(cx, alloc), alloc))