From f7e11cba36abb4da04497c7db9c536df78c3cc51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Mi=C4=85sko?= <tomasz.miasko@gmail.com>
Date: Fri, 6 Nov 2020 00:00:00 +0000
Subject: [PATCH] inliner: Use substs_for_mir_body

Changes from 68965 extended the kind of instances that are being
inlined. For some of those, the `instance_mir` returns a MIR body that
is already expressed in terms of the types found in substitution array,
and doesn't need further substitution.

Use `substs_for_mir_body` to take that into account.
---
 src/common.rs | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/common.rs b/src/common.rs
index eda77bf19d3..466758f2f86 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -361,13 +361,11 @@ impl<'tcx, M: Module> FunctionCx<'_, 'tcx, M> {
     where
         T: TypeFoldable<'tcx> + Copy,
     {
-        if let Some(substs) = self.instance.substs_for_mir_body() {
-            self.tcx
-                .subst_and_normalize_erasing_regions(substs, ty::ParamEnv::reveal_all(), value)
-        } else {
-            self.tcx
-                .normalize_erasing_regions(ty::ParamEnv::reveal_all(), *value)
-        }
+        self.instance.subst_mir_and_normalize_erasing_regions(
+            self.tcx,
+            ty::ParamEnv::reveal_all(),
+            value
+        )
     }
 
     pub(crate) fn clif_type(&self, ty: Ty<'tcx>) -> Option<Type> {