Accidentally failed to commit these earlier, as part of:

Accidentally failed to commit these earlier, as part of:

    Update the compiler to use the new names.  Add calls to printlock and
    printunlock around print statements.  Move expression evaluation before
    the call to printlock.  Update g's writebuf field to a slice, and adjust
    C code accordingly.

    Reviewed-on: https://go-review.googlesource.com/30717

From-SVN: r240958