Rust 2024 compatibility

[nunoplopes]

Rust 2024 doesn't allow references to static mut variables. Some tests fail:

********************
FAIL: cpp2rust :: unit/bool_condition_logical.cpp/unsafe (24 of 634)
******************** TEST 'cpp2rust :: unit/bool_condition_logical.cpp/unsafe' FAILED ********************
rustc failed
error: creating a mutable reference to mutable static
  --> main.rs:28:5
   |
28 |     side_effect.prefix_inc();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^ mutable reference to mutable static
   |
   = note: mutable references to mutable statics are dangerous; it's undefined behavior if any other pointer to the static is used or if any other reference is created for the static while the mutable reference lives
   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2024/static-mut-references.html>
   = note: `#[deny(static_mut_refs)]` (part of `#[deny(rust_2024_compatibility)]`) on by default

error: aborting due to 1 previous error

After fixing this, remove -W static_mut_refs from the Cpp2RustTest.py test driver.

[nunoplopes]

Woff2 also fails:

   Compiling woff2_unsafe v0.1.0 (/home/nuno.lopes/testsuite/woff2/out/unsafe)
error: creating a shared reference to mutable static
    --> src/bin/woff2_info.rs:1433:9
     |
1433 |         &woff2_kDsigTableTag,
     |         ^^^^^^^^^^^^^^^^^^^^ shared reference to mutable static
     |
     = note: shared references to mutable statics are dangerous; it's undefined behavior if the static is mutated or if a mutable reference is created for it while the shared reference lives
     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2024/static-mut-references.html>
     = note: `#[deny(static_mut_refs)]` (part of `#[deny(rust_2024_compatibility)]`) on by default
help: use `&raw const` instead to create a raw pointer
     |
1433 |         &raw const woff2_kDsigTableTag,
     |          +++++++++

error: could not compile `woff2_unsafe` (bin "woff2_info") due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: creating a shared reference to mutable static
    --> src/bin/woff2_decompress.rs:3250:36
     |
3250 |             (*if *&mut __tmp_0 <= *&woff2_kDefaultMaxSize {
     |                                    ^^^^^^^^^^^^^^^^^^^^^^ shared reference to mutable static
     |
     = note: shared references to mutable statics are dangerous; it's undefined behavior if the static is mutated or if a mutable reference is created for it while the shared reference lives
     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2024/static-mut-references.html>
     = note: `#[deny(static_mut_refs)]` (part of `#[deny(rust_2024_compatibility)]`) on by default
help: use `&raw const` instead to create a raw pointer
     |
3250 |             (*if *&mut __tmp_0 <= *&raw const woff2_kDefaultMaxSize {
     |                                     +++++++++

error: creating a shared reference to mutable static
    --> src/bin/woff2_decompress.rs:3253:17
     |
3253 |                 (&woff2_kDefaultMaxSize) as *const _
     |                 ^^^^^^^^^^^^^^^^^^^^^^^^ shared reference to mutable static
     |
     = note: shared references to mutable statics are dangerous; it's undefined behavior if the static is mutated or if a mutable reference is created for it while the shared reference lives
     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2024/static-mut-references.html>
help: use `&raw const` instead to create a raw pointer
     |
3253 |                 (&raw const woff2_kDefaultMaxSize) as *const _
     |                   +++++++++

error: could not compile `woff2_unsafe` (bin "woff2_decompress") due to 2 previous errors
error: creating a shared reference to mutable static
    --> src/bin/woff2_compress.rs:1433:9
     |
1433 |         &woff2_kDsigTableTag,
     |         ^^^^^^^^^^^^^^^^^^^^ shared reference to mutable static
     |
     = note: shared references to mutable statics are dangerous; it's undefined behavior if the static is mutated or if a mutable reference is created for it while the shared reference lives
     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2024/static-mut-references.html>
     = note: `#[deny(static_mut_refs)]` (part of `#[deny(rust_2024_compatibility)]`) on by default
help: use `&raw const` instead to create a raw pointer
     |
1433 |         &raw const woff2_kDsigTableTag,
     |          +++++++++

error: could not compile `woff2_unsafe` (bin "woff2_compress") due to 1 previous error