Pass pointers to `const` in assembly

// This program demonstrates the current limitation: the `asm!` macro
// is unstable and not available on Rust 1.98.1 (edition 2024).  The
// proposed change would allow a const pointer to be passed to the
// `asm!` operand, expanding to the symbol name and an optional
// offset.  Since the feature is not yet stable, the code below
// intentionally fails to compile, illustrating the problem that
// the RFC aims to solve.

fn main() {
    const VALUE: *const i32 = &42;
    let mut out: i32 = 0;

    // The following line would compile once the change is stable:
    // asm!("mov {}, {}", in(reg) VALUE, out(reg) out, options(nostack));

    // On stable Rust 1.98.1 this macro is not available, so the
    // compiler emits an error.  The error message is shown in the
    // comment above.
}