inliner: Use substs_for_mir_body

[tmiasko]

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.

Resolves #78529.
Resolves #78560.

[bors]

☔ The latest upstream changes (presumably #78697) made this pull request unmergeable. Please resolve the merge conflicts.

Note that reviewers usually do not review pull requests until merge conflicts are resolved! Once you resolve the conflicts, you should change the labels applied by bors to indicate that your PR is ready for review. Post this as a comment to change the labels:

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[oli-obk]

@bors r+

Thanks!

[bors]

📌 Commit d2bc8a9 has been approved by oli-obk

[oli-obk]

@bors r-

[oli-obk]

@bors delegate+

r=me with the documentation nit resolved.

[bors]

✌️ @tmiasko can now approve this pull request

[oli-obk]

@bors r+

[bors]

📌 Commit d2bc8a9 has been approved by oli-obk

[jyn514]

@bors r-

Failed in rollup:

---- [mir-opt] mir-opt/inline/inline-shims.rs stdout ----
9	      let mut _4: *mut std::vec::Vec<A>;   // in scope 0 at $DIR/inline-shims.rs:10:38: 10:39
10	      let mut _5: *mut std::option::Option<B>; // in scope 0 at $DIR/inline-shims.rs:11:38: 11:39
11	      scope 1 {
+	+         scope 3 (inlined drop_in_place::<Vec<A>> - shim(Some(Vec<A>))) { // at $DIR/inline-shims.rs:10:14: 10:40
+	+             let mut _6: &mut std::vec::Vec<A>; // in scope 3 at $DIR/inline-shims.rs:10:14: 10:40
+	+             let mut _7: ();              // in scope 3 at $DIR/inline-shims.rs:10:14: 10:40
+	+         }
12	      }
13	      scope 2 {
-	+         scope 3 (inlined drop_in_place::<Option<B>> - shim(Some(Option<B>))) { // at $DIR/inline-shims.rs:11:14: 11:40
-	+             let mut _6: isize;           // in scope 3 at $DIR/inline-shims.rs:11:14: 11:40
-	+             let mut _7: isize;           // in scope 3 at $DIR/inline-shims.rs:11:14: 11:40
+	+         scope 4 (inlined drop_in_place::<Option<B>> - shim(Some(Option<B>))) { // at $DIR/inline-shims.rs:11:14: 11:40
+	+             let mut _8: isize;           // in scope 4 at $DIR/inline-shims.rs:11:14: 11:40
+	+             let mut _9: isize;           // in scope 4 at $DIR/inline-shims.rs:11:14: 11:40
17	+         }
18	      }
19	  

21	          StorageLive(_3);                 // scope 0 at $DIR/inline-shims.rs:10:5: 10:42
22	          StorageLive(_4);                 // scope 1 at $DIR/inline-shims.rs:10:38: 10:39
23	          _4 = _1;                         // scope 1 at $DIR/inline-shims.rs:10:38: 10:39
-	          _3 = drop_in_place::<Vec<A>>(move _4) -> bb1; // scope 1 at $DIR/inline-shims.rs:10:14: 10:40
+	-         _3 = drop_in_place::<Vec<A>>(move _4) -> bb1; // scope 1 at $DIR/inline-shims.rs:10:14: 10:40
+	+         _6 = &mut (*_4);                 // scope 3 at $DIR/inline-shims.rs:10:14: 10:40
+	+         _7 = <Vec<A> as Drop>::drop(move _6) -> bb2; // scope 3 at $DIR/inline-shims.rs:10:14: 10:40
25	                                           // mir::Constant
-	                                           // + span: $DIR/inline-shims.rs:10:14: 10:37
-	                                           // + literal: Const { ty: unsafe fn(*mut std::vec::Vec<A>) {std::intrinsics::drop_in_place::<std::vec::Vec<A>>}, val: Value(Scalar(<ZST>)) }
+	-                                          // + span: $DIR/inline-shims.rs:10:14: 10:37
+	-                                          // + literal: Const { ty: unsafe fn(*mut std::vec::Vec<A>) {std::intrinsics::drop_in_place::<std::vec::Vec<A>>}, val: Value(Scalar(<ZST>)) }
+	+                                          // + span: $DIR/inline-shims.rs:10:14: 10:40
+	+                                          // + literal: Const { ty: for<'r> fn(&'r mut std::vec::Vec<A>) {<std::vec::Vec<A> as std::ops::Drop>::drop}, val: Value(Scalar(<ZST>)) }
28	      }
29	  
30	      bb1: {

36	-                                          // mir::Constant
37	-                                          // + span: $DIR/inline-shims.rs:11:14: 11:37
38	-                                          // + literal: Const { ty: unsafe fn(*mut std::option::Option<B>) {std::intrinsics::drop_in_place::<std::option::Option<B>>}, val: Value(Scalar(<ZST>)) }
-	+         _6 = discriminant((*_5));        // scope 3 at $DIR/inline-shims.rs:11:14: 11:40
-	+         switchInt(move _6) -> [0_isize: bb2, otherwise: bb3]; // scope 3 at $DIR/inline-shims.rs:11:14: 11:40
+	+         _8 = discriminant((*_5));        // scope 4 at $DIR/inline-shims.rs:11:14: 11:40
+	+         switchInt(move _8) -> [0_isize: bb3, otherwise: bb4]; // scope 4 at $DIR/inline-shims.rs:11:14: 11:40
41	      }
42	  
43	      bb2: {

+	+         drop(((*_4).0: alloc::raw_vec::RawVec<A>)) -> bb1; // scope 3 at $DIR/inline-shims.rs:10:14: 10:40
+	+     }
+	+ 
+	+     bb3: {
44	          StorageDead(_5);                 // scope 2 at $DIR/inline-shims.rs:11:39: 11:40
45	          return;                          // scope 0 at $DIR/inline-shims.rs:12:2: 12:2
46	+     }

47	+ 
-	+     bb3: {
-	+         drop((((*_5) as Some).0: B)) -> bb2; // scope 3 at $DIR/inline-shims.rs:11:14: 11:40
+	+     bb4: {
+	+         drop((((*_5) as Some).0: B)) -> bb3; // scope 4 at $DIR/inline-shims.rs:11:14: 11:40
50	      }
51	  }
52	  

thread '[mir-opt] mir-opt/inline/inline-shims.rs' panicked at 'Actual MIR output differs from expected MIR output /checkout/src/test/mir-opt/inline/inline_shims.drop.Inline.diff', src/tools/compiletest/src/runtest.rs:3272:25
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[oli-obk]

@tmiasko you still have delegation rights, so r=me after a rebase

[tmiasko]

Ignored new tests on wasm target.

@bors r=oli-obk

[bors]

📌 Commit 8a8ee1a has been approved by oli-obk