Auto merge of #2209 - RalfJung:if-only, r=RalfJung

hotfix for incorrect only- logic

This hacks around #2206. We don't currently use `only-32bit` or so, which is why this works.

tests/fail/concurrency/thread-spawn.stderr

@@ -0,0 +1,30 @@
+error: unsupported operation: can't create threads on Windows
+  --> RUSTLIB/std/src/sys/PLATFORM/thread.rs:LL:CC
+   |
+LL |           let ret = c::CreateThread(
+   |  ___________________^
+LL | |             ptr::null_mut(),
+LL | |             stack,
+LL | |             thread_start,
+...  |
+LL | |             ptr::null_mut(),
+LL | |         );
+   | |_________^ can't create threads on Windows
+   |
+   = help: this is likely not a bug in the program; it indicates that the program performed an operation that the interpreter does not support
+
+   = note: inside `std::sys::PLATFORM::thread::Thread::new` at RUSTLIB/std/src/sys/PLATFORM/thread.rs:LL:CC
+   = note: inside `std::thread::Builder::spawn_unchecked_::<[closure@$DIR/thread-spawn.rs:LL:CC], ()>` at RUSTLIB/std/src/thread/mod.rs:LL:CC
+   = note: inside `std::thread::Builder::spawn_unchecked::<[closure@$DIR/thread-spawn.rs:LL:CC], ()>` at RUSTLIB/std/src/thread/mod.rs:LL:CC
+   = note: inside `std::thread::Builder::spawn::<[closure@$DIR/thread-spawn.rs:LL:CC], ()>` at RUSTLIB/std/src/thread/mod.rs:LL:CC
+   = note: inside `std::thread::spawn::<[closure@$DIR/thread-spawn.rs:LL:CC], ()>` at RUSTLIB/std/src/thread/mod.rs:LL:CC
+note: inside `main` at $DIR/thread-spawn.rs:LL:CC
+  --> $DIR/thread-spawn.rs:LL:CC
+   |
+LL |     thread::spawn(|| {});
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to previous error
+

ui_test/src/lib.rs

@@ -516,9 +516,10 @@ fn ignore_file(comments: &Comments, target: &str) -> bool {
         if !target.contains(s) {
             return true;
         }
+        /* FIXME(https://github.com/rust-lang/miri/issues/2206)
         if get_pointer_width(target) != s {
             return true;
-        }
+        } */
     }
     false
 }