Log Message:
Update to 5.0.1.  There is no changelog in the tarball, because it is a
pre-release.  However, it is unlikely to change for the final release of
5.0.1.

Fixed bugs:
    1. lua_closethread exists only in the manual
    2. attempt to resume a running coroutine crashes Lua
    3. file:close cannot be called without a file. (results in seg. fault)
    4. C functions may have stacks larger than current top
    5. `pc' address is invalidated when a coroutine is suspended
    6. userdata to be collected still counts into new GC threshold,
       increasing memory consumption
    7. IBM AS400 (OS400) has sizeof(void *)==16, and a `%p' may generate up
       to 60 characters in a `printf'. That causes a buffer overflow in
       `tostring'.
    8. syntax `local function' does not increment stack size
    9. count hook may be called without being set