rustfmt `tests/mir-opt`.

The only non-obvious changes:
- `building/storage_live_dead_in_statics.rs` has a `#[rustfmt::skip]`
  attribute to avoid reformating a table of data.
- Two `.mir` files have slight changes involving line numbers.
- In `unusual_item_types.rs` an `EMIT_MIR` annotation is moved to
  outside a function, which is the usual spot, because `tidy` complains
  if such a comment is indented.

The commit also tweaks the comments in `rustfmt.toml`.

1 files changed, 4 insertions, 3 deletions

diff --git a/tests/mir-opt/nll/named_lifetimes_basic.rs b/tests/mir-opt/nll/named_lifetimes_basic.rs
index cc838537003..93f4a8bfd59 100644
--- a/tests/mir-opt/nll/named_lifetimes_basic.rs
+++ b/tests/mir-opt/nll/named_lifetimes_basic.rs
@@ -10,7 +10,8 @@
 #![allow(warnings)]
 
 // EMIT_MIR named_lifetimes_basic.use_x.nll.0.mir
-fn use_x<'a, 'b: 'a, 'c>(w: &'a mut i32, x: &'b u32, y: &'a u32, z: &'c u32) -> bool { true }
-
-fn main() {
+fn use_x<'a, 'b: 'a, 'c>(w: &'a mut i32, x: &'b u32, y: &'a u32, z: &'c u32) -> bool {
+    true
 }
+
+fn main() {}