You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: register_alloc.rs
    path of file: ./repos/wasmi/crates/wasmi/src/engine/translator/stack
    
    the code of the file until where you have to start completion: use super::{TaggedProvider, TypedProvider};
use crate::{
    engine::{
        bytecode::{Register, RegisterSpan},
        TranslationError,
    },
    Error,
};
use core::{
    cmp::{max, min},
    num::NonZeroUsize,
};
use multi_stash::{Key, Key as StashKey, MultiStash};
use std::collections::BTreeSet;

#[cfg(doc)]
use crate::engine::translator::InstrEncoder;

/// The register allocator using during translation.
///
/// # Note
///
/// This has 
    
    pub fn register_locals(&mut self, amount: u32) -> Result<(), Error> {
        /// Bumps `len_locals` by `amount` if possible.
        fn bump_locals(len_locals: u16, amount: u32) -> Option<u16> {
            let amount = u16::try_from(amount).ok()?;
            let new_len = len_locals.checked_add(amount)?;
            if new_len >= RegisterAlloc::MAX_LEN_LOCALS {
                return None;
            }
            Some(new_len)
        }
        assert!(matches!(self.phase, AllocPhase::Init));
        self.len_locals = bump_locals(self.len_locals, amount)
            .ok_or_else(|| Error::from(TranslationError::AllocatedTooManyRegisters))?;
        // We can convert `len_locals` to `i16` because it is always without bounds of `0..i16::MAX`.
        self.next_dynamic = self.len_locals as i16;
        self.max_dynamic = self.len_locals as i16;
        Ok(())
    }