Rollup merge of #120302 - oli-obk:const_intern_cleanups, r=RalfJung

various const interning cleanups

After #119044 I noticed that some things can be simplified and refactored.

This is also a requirement for https://github.com/rust-lang/rust/pull/116564 as there we'll need to treat the base allocation differently from the others

r? ````@RalfJung````

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -1,5 +1,3 @@
-use std::mem;
-
 use either::{Left, Right};
 
 use rustc_hir::def::DefKind;
@@ -24,12 +22,13 @@ use crate::interpret::{
 };
 
 // Returns a pointer to where the result lives
+#[instrument(level = "trace", skip(ecx, body), ret)]
 fn eval_body_using_ecx<'mir, 'tcx>(
     ecx: &mut CompileTimeEvalContext<'mir, 'tcx>,
     cid: GlobalId<'tcx>,
     body: &'mir mir::Body<'tcx>,
 ) -> InterpResult<'tcx, MPlaceTy<'tcx>> {
-    debug!("eval_body_using_ecx: {:?}, {:?}", cid, ecx.param_env);
+    trace!(?ecx.param_env);
     let tcx = *ecx.tcx;
     assert!(
         cid.promoted.is_some()
@@ -75,11 +74,8 @@ fn eval_body_using_ecx<'mir, 'tcx>(
             None => InternKind::Constant,
         }
     };
-    let check_alignment = mem::replace(&mut ecx.machine.check_alignment, CheckAlignment::No); // interning doesn't need to respect alignment
     intern_const_alloc_recursive(ecx, intern_kind, &ret)?;
-    ecx.machine.check_alignment = check_alignment;
 
-    debug!("eval_body_using_ecx done: {:?}", ret);
     Ok(ret)
 }