Method replace_op

crates/compiler-core/src/bytecode.rs:653–657

Replace the opcode at `index` in-place without changing the arg byte. Uses atomic Release store to ensure prior cache writes are visible to threads that subsequently read the new opcode with Acquire. # Safety - `index` must be in bounds. - `new_op` must have the same arg semantics as the original opcode.

(&self, index: usize, new_op: Instruction)

    /// - `index` must be in bounds.
    /// - `new_op` must have the same arg semantics as the original opcode.
    pub unsafe fn replace_op(&self, index: usize, new_op: Instruction) {
        let units = unsafe { &*self.units.get() };
        let ptr = units.as_ptr().wrapping_add(index) as *const AtomicU8;
        unsafe { &*ptr }.store(new_op.into(), Ordering::Release);
    }

    /// Atomically replace opcode only if it still matches `expected`.
    /// Returns true on success. Uses Release ordering on success.