Reworked `SimulatedClassPool >> #associationAt:ifAbsent:` to throw an error
...if there's no such class variable. This makes it behave more like
dictionary / pool.
LIBRARY libbasic
DESCRIPTION 'Smalltalk/X Basic classes'
VERSION 3.5
CODE EXECUTE READ
DATA READ WRITE
SECTIONS
INITCODE READ EXECUTE
INITDATA READ WRITE
EXPORTS
_libbasic_Init