Fix conflicts after rebase

- r-l/r 126784
- r-l/r 127113
- r-l/miri 3562

compiler/rustc_middle/src/mir/syntax.rs

@@ -767,7 +767,7 @@ pub enum TerminatorKind<'tcx> {
         /// These are owned by the callee, which is free to modify them.
         /// This allows the memory occupied by "by-value" arguments to be
         /// reused across function calls without duplicating the contents.
-        args: Vec<Spanned<Operand<'tcx>>>,
+        args: Box<[Spanned<Operand<'tcx>>]>,
         // FIXME(explicit_tail_calls): should we have the span for `become`? is this span accurate? do we need it?
         /// This `Span` is the span of the function, without the dot and receiver
         /// (e.g. `foo(a, b)` in `x.foo(a, b)`