Revert "Auto merge of #102417 - oli-obk:opaque_lifetimes2, r=jackh726"

This reverts commit cb9467515b5a9b15aaa905683c6b4dd9e851056c, reversing
changes made to 57781b24c54f9548722927ba88c343ff28da94ce.

1 files changed, 9 insertions, 1 deletions

diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index d91d9fcbc8e..d69d7ff904a 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -129,7 +129,15 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
 
     // By default, RPIT are invariant wrt type and const generics, but they are bivariant wrt
     // lifetime generics.
-    let mut variances: Vec<_> = std::iter::repeat(ty::Invariant).take(generics.count()).collect();
+    let variances = std::iter::repeat(ty::Invariant).take(generics.count());
+
+    let mut variances: Vec<_> = match tcx.opaque_type_origin(item_def_id) {
+        rustc_hir::OpaqueTyOrigin::FnReturn(_) | rustc_hir::OpaqueTyOrigin::AsyncFn(_) => {
+            variances.collect()
+        }
+        // But TAIT are invariant for all generics
+        rustc_hir::OpaqueTyOrigin::TyAlias { .. } => return tcx.arena.alloc_from_iter(variances),
+    };
 
     // Mark all lifetimes from parent generics as unused (Bivariant).
     // This will be overridden later if required.