Rollup merge of #69981 - oli-obk:const_blocks, r=eddyb

Evaluate repeat expression lengths as late as possible

Fixes #68567

r? @varkor

diff --cc src/librustc/mir/interpret/mod.rs
Simple merge

diff --cc src/librustc/mir/mod.rs
Simple merge

diff --cc src/librustc/ty/sty.rs
index 0c14580717f92c0e9fc5bc0d2878c76df84657a9,cfd99cbbb9feffb34a44b5f2c54ecade74e6483d..10c5431e2fc1e99eca86caf4b3a41f783c07f524
--- 1/src/librustc/ty/sty.rs
--- 2/src/librustc/ty/sty.rs
+++ b/src/librustc/ty/sty.rs
@@@ -8,10 -8,10 +8,10 @@@ use self::TyKind::*
  use crate::infer::canonical::Canonical;
  use crate::middle::region;
  use crate::mir::interpret::ConstValue;
- use crate::mir::interpret::Scalar;
+ use crate::mir::interpret::{LitToConstInput, Scalar};
  use crate::mir::Promoted;
  use crate::ty::layout::VariantIdx;
 -use crate::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, Subst, SubstsRef};
 +use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef};
  use crate::ty::{
      self, AdtDef, DefIdTree, Discr, Ty, TyCtxt, TypeFlags, TypeFoldable, WithConstness,
  };

diff --cc src/librustc_mir/borrow_check/type_check/mod.rs
Simple merge

diff --cc src/librustc_mir_build/hair/cx/expr.rs
Simple merge

diff --cc src/librustc_typeck/astconv.rs
Simple merge

diff --cc src/librustc_typeck/check/expr.rs
Simple merge

diff --cc src/librustc_typeck/check/mod.rs
Simple merge