Evaluate condition default initargs once, even after redefinition

Evaluate condition default initargs once, even after redefinition

There were two causes of this failure

* %DEFINE-CONDITION did not clear CONDITION-CLASSOID-HAIRY-SLOTS when
  a condition was redefined. This led to multiple copies of slots in
  CONDITION-CLASSOID-HAIRY-SLOTS and thus to initforms being evaluated
  multiple times. %DEFINE-CONDITION now clears
  CONDITION-CLASSOID-HAIRY-SLOTS before populating it again.

* (MAKE-INSTANCE CONDITION-CLASS) produced the call tree
  MAKE-INSTANCE
  + ALLOCATE-INSTANCE SLOT-OBJECT
    + MAKE-CONDITION
  + INITIALIZE-INSTANCE SLOT-OBJECT
    + SHARED-INITIALIZE SLOT-OBJECT
  MAKE-CONDITION  and SHARED-INITIALIZE both called initfunctions
  leading to multiple evaluations

A test case has been added.

fixes lp#1164969