consistent folder naming: stacked-borrows -> stacked_borrows

Author: RalfJung

src/tools/miri/tests/pass/both_borrows/2phase.rs

@@ -1,9 +1,6 @@
 //@revisions: stack tree
 //@[tree]compile-flags: -Zmiri-tree-borrows
 
-// FIXME: this miscompiles with optimizations, see <https://github.com/rust-lang/rust/issues/132898>.
-//@compile-flags: -Zmir-opt-level=0
-
 trait S: Sized {
     fn tpb(&mut self, _s: Self) {}
 }
@@ -34,9 +31,9 @@ fn two_phase3(b: bool) {
     ));
 }
 
-#[allow(unreachable_code)]
 fn two_phase_raw() {
     let x: &mut Vec<i32> = &mut vec![];
+    #[allow(unreachable_code)] // The `push` itself never gets reached.
     x.push({
         // Unfortunately this does not trigger the problem of creating a
         // raw ponter from a pointer that had a two-phase borrow derived from

src/tools/miri/tests/pass/stacked-borrows/coroutine-self-referential.rs renamed to src/tools/miri/tests/pass/stacked_borrows/coroutine-self-referential.rs

@@ -1,5 +1,5 @@
 warning: integer-to-pointer cast
-  --> tests/pass/stacked-borrows/issue-miri-2389.rs:LL:CC
+  --> tests/pass/stacked_borrows/issue-miri-2389.rs:LL:CC
    |
 LL |         let wildcard = &root0 as *const Cell<i32> as usize as *const Cell<i32>;
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ integer-to-pointer cast
@@ -10,5 +10,5 @@ LL |         let wildcard = &root0 as *const Cell<i32> as usize as *const Cell<i
    = help: you can then set `MIRIFLAGS=-Zmiri-strict-provenance` to ensure you are not relying on `with_exposed_provenance` semantics
    = help: alternatively, `MIRIFLAGS=-Zmiri-permissive-provenance` disables this warning
    = note: BACKTRACE:
-   = note: inside `main` at tests/pass/stacked-borrows/issue-miri-2389.rs:LL:CC
+   = note: inside `main` at tests/pass/stacked_borrows/issue-miri-2389.rs:LL:CC
 

src/tools/miri/tests/pass/stacked-borrows/int-to-ptr.rs renamed to src/tools/miri/tests/pass/stacked_borrows/int-to-ptr.rs

@@ -1,3 +1,6 @@
+// FIXME: this miscompiles with optimizations, see <https://github.com/rust-lang/rust/issues/132898>.
+//@compile-flags: -Zmir-opt-level=0
+
 // Test various stacked-borrows-specific things
 // (i.e., these do not work the same under TB).
 fn main() {