Re: [PATCH 1/6] Remove some manual memory management from compile interface

[Tom Tromey <tom@tromey.com>]

Simon> You could now remove this `if (num_baseclasses > 0)`, there's no
Simon> reason for it anymore I think.

I looked at this more deeply, and based on the compiler library, I think
the rule is that a 0-length array should be passed as nullptr here:

  status
  marshall (connection *conn, const gcc_vbase_array *a)
  {
    size_t len;

    if (a)
      len = a->n_elements;
    else
      len = (size_t)-1;

    if (!marshall_array_start (conn, 'v', len))
      return FAIL;

    if (!a)
      return OK;
   [...]


So, I changed this code to use your suggestion and then also modified
the final call:

      result = instance->plugin ().start_class_type
	(name.get (), resuld, num_baseclasses > 0 ? &bases : nullptr,
	 filename, line);

This didn't result in any test result changes, but I didn't look to see
if this case is not tested or something like that.

Tom