Compat resolver can't handle module.pmod

Imported from http://bugzilla.roxen.com/bugzilla/show_bug.cgi?id=7364

Reported by Martin Nilsson nilsson@opera.com

A very simple example is in the 8.0 compat code for Locale in 8.1. The Locale.pmod/module.pmod file essentially only contains

#pike 8.1
inherit Locale;
object Charset = global.Charset;

but when accessed creates the following error

Pike v8.1 release 0 running Hilfe v3.5 (Incremental Pike Frontend)
(running in Pike 8.0 compat mode)
> Locale;            
(1) Result: Locale
> indices(Locale);
Bad argument 1.
Unknown program: foreach(UNDEFINED)
master.pike:2233:
    master()->joinnode(0).create(UNDEFINED,UNDEFINED,UNDEFINED,UNDEFINED)     
-:1: PikeCompiler("", UNDEFINED, 8, -1, target, placeholder)->compile()
-:1:
    DefaultCompilerEnvironment->compile(PikeCompiler("", UNDEFINED, 8, -1, tar
    get, placeholder))                                                        
master.pike:675:
    compile_string("#pike 8.1\n\ninherit Locale;\n\n//! @module Charset\n//!\n
    //!   This is the old loca"+[162],"/home/nilsson/pike/lib/8.0/modules/Loca
    le.pmod/module.pmod",0,object_program(8.0::Locale),master()->joinnode(0),U
    NDEFINED)                                                                 
master.pike:1378:
    master()->low_findprog("/home/nilsson/pike/lib/8.0/modules/Locale.pmod/mod
    ule.pmod","",0,1)                                                         
master.pike:1501:
    master()->findprog("/home/nilsson/pike/lib/8.0/modules/Locale.pmod/module.
    pmod",".pmod",0,1)                                                        
master.pike:1535:
    master()->low_cast_to_program("/home/nilsson/pike/lib/8.0/modules/Locale.p
    mod/module",0,0,1)