Don't format tests/run-make/*/rmake.rs.

It's reasonable to want to, but in the current implementation this causes multiple problems. - All the `rmake.rs` files are formatted every time even when they haven't changed. This is because they get whitelisted unconditionally in the `OverrideBuilder`, before the changed files get added. - The way `OverrideBuilder` works, if any files gets whitelisted then no unmentioned files will get traversed. This is surprising, and means that the `rmake.rs` entries broke the use of explicit paths to `x fmt`, and also broke `GITHUB_ACTIONS=true git check --fmt`. The commit removes the `rmake.rs` entries, fixes the formatting of a couple of files that were misformatted (not previously caught due to the `GITHUB_ACTIONS` breakage), and bans `!`-prefixed entries in `rustfmt.toml` because they cause all these problems.

Author: nnethercote

core/src/ptr/metadata.rs

@@ -209,18 +209,14 @@ impl<Dyn: ?Sized> DynMetadata<Dyn> {
  // Consider a reference like `&(i32, dyn Send)`: the vtable will only store the size of the
  // `Send` part!
  // SAFETY: DynMetadata always contains a valid vtable pointer
- return unsafe {
- crate::intrinsics::vtable_size(self.vtable_ptr() as *const ())
- };
+ return unsafe { crate::intrinsics::vtable_size(self.vtable_ptr() as *const ()) };
  }
 
  /// Returns the alignment of the type associated with this vtable.
  #[inline]
  pub fn align_of(self) -> usize {
  // SAFETY: DynMetadata always contains a valid vtable pointer
- return unsafe {
- crate::intrinsics::vtable_align(self.vtable_ptr() as *const ())
- };
+ return unsafe { crate::intrinsics::vtable_align(self.vtable_ptr() as *const ()) };
  }
 
  /// Returns the size and alignment together as a `Layout`