configure and defines

[Martin Nilsson (Opera Mini - AFK!) @ Pike (-) developers forum]

Perhpas more a philisophical question, but do we really need configure
tests for .h file defines. I just saw masts commit of testing for the
existance of FIELD_TYPE_BIT and then doing

#ifdef HAVE_FIELD_TYPE_BIT
    case FIELD_TYPE_BIT:
#else
    case 16:
#endif

wouldn't no configure test and a

#ifndef FIELD_TYPE_BIT
#define FIELD_TYPE_BIT 16
#endif

had had the same result?