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: lib.rs
    path of file: ./repos/wasm-bindgen/src
    
    the code of the file until where you have to start completion: //! Runtime support for the `wasm-bindgen` tool
//!
//! This crate contains the runtime support necessary for `wasm-bindgen` the
//! attribute and tool. Crates pull in the `#[wasm_bindgen]` attribute through
//! this crate and this crate also provides JS bindings through the `JsValue`
//! interface.

#![no_std]
#![allow(coherence_leak_check)]
#![doc(html_root_url = "https://d
    
        pub unsafe extern "C" fn __wbindgen_realloc(ptr: *mut u8, old_size: usize, new_size: usize, align: usize) -> *mut u8 {
            debug_assert!(old_size > 0);
            debug_assert!(new_size > 0);
            if let Ok(layout) = Layout::from_size_align(old_size, align) {
                let ptr = realloc(ptr, layout, new_size);
                if !ptr.is_null() {
                    return ptr
                }
            }
            malloc_failure();
        }