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`.
The test cases src/test/mir-opt/building/custom/consts.rs and
src/test/mir-opt/const_prop/mutable_variable_no_prop.rs are
currently failing on big-endian platforms as the binary encoding
of some constants is hard-coded in the MIR test files. Fix this
by choosing constant values that have the same encoding on big-
and little-endian platforms.
The test case src/test/mir-opt/issues/issue_75439.rs is failing
as well, but since the purpose of the test is to validate handling
of big-endian integer encodings on a little-endian platform, it does
not make much sense to run it on big-endian platforms in the first
place - we can just ignore it there.
Fixed part of https://github.com/rust-lang/rust/issues/105383.
