Fix clippy::ref_as_ptr for non-temporary references in let/const

[Abd002]

Fix ref_as_ptr lint: ignore casts used to initialize const/static/let bindings and avoid linting temporary values.

• Do not lint &STATIC_I32 as *const _ and &val as *const _ when used to initialize const/static/let.
• Still lint other &T as *const U / &mut T as *mut U casts and suggest std::ptr::from_ref / from_mut.

[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

[rustbot]

r? @Mark-Simulacrum

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[Kivooeo]

The development of Clippy happens in its own repo - https://github.com/rust-lang/rust-clippy