Auto merge of #38574 - Mark-Simulacrum:box-free-unspecialize, r=eddyb

Remove special case for Box<ZST> in trans

Remove extra lang item, `exchange_free`; use `box_free` instead.

Trans used to insert code equivalent to `box_free` in a wrapper around
`exchange_free`, and that code is now removed from trans.

Fixes #37710.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/liballoc/heap.rs b/src/liballoc/heap.rs
index a1e32636980..81ed4be7763 100644
--- a/src/liballoc/heap.rs
+++ b/src/liballoc/heap.rs
@@ -144,6 +144,7 @@ unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 {
 }
 
 #[cfg(not(test))]
+#[cfg(stage0)]
 #[lang = "exchange_free"]
 #[inline]
 unsafe fn exchange_free(ptr: *mut u8, old_size: usize, align: usize) {