failure compiling coroutine.cpp when coro guard enabled

[Stephen Bannasch]

I'm getting this error compiling coroutine.cpp when I add "coro" to my guards

   coroutine.cpp:111: error: 'startInternal_method_name' is not a member of 'vmSymbols'

That's with these guards:

   export guards="buildable testable coro"

This is on Mac OS X 10.6.8 and 10.7.4.

MLVM builds and runs fine with just these guards:

     export guards="buildable testable"

Using update.sh as a build script from: https://gist.github.com/243072

** many updates to build script, supports arguments to script

    I now compile MLVM with coro like this:

      ./update.sh --coro

Console output for both 10.6.8 and 10.7.4 here (different compilers used): https://gist.github.com/3118989