message: Make localeconv return mutable pointer, matching specification
diff: @@ -32,7 +32,8 @@ pub struct lconv {
  }
  unsafe impl Sync for lconv {}
  -static CURRENT_LOCALE: lconv = lconv {
  +//TODO: thread local?
  +static mut CURRENT_LOCALE: lconv = lconv {
  currency_symbol: EMPTY_PTR,
  decimal_point: ".\0" as *const _ as *const c_char,
  frac_digits: c_char::max_value(),
  @@ -54,8 +55,8 @@ static CURRENT_LOCALE: lconv = lconv {
  };
  #[no_mangle]
  -pub extern "C" fn localeconv() -> *const lconv {
  - &CURRENT_LOCALE as *const _
  +pub unsafe extern "C" fn localeconv() -> *mut lconv {
  + &mut CURRENT_LOCALE as *mut _
  }
  #[no_mangle]
  