Fix memory leak in @synchronized.

This was actually a memory leak in the hidden class implementation, but
it was mostly visible in the @synchronized implementation.  Every hidden
class registered a custom .cxx_destruct method, to handle cleanup of all
of the hidden class structures.  Unfortunately, this destructor failed
to delete the reflection metadata structures associated with the class,
specifically the objc_method_list containing the objc_method pointing to
the destructor itself.

Fixes gnustep#98

Author: davidchisnall

associate.m

@@ -275,6 +275,9 @@ static void deallocHiddenClass(id obj, SEL _cmd)
 		}
 	}
 	obj->isa = hiddenClass->super_class;
+	// Free the introspection structures:
+	freeMethodLists(hiddenClass);
+	freeIvarLists(hiddenClass);
 	// Free the class
 	free(hiddenClass);
 }

class.h

@@ -434,4 +434,13 @@ static inline BOOL classIsOrInherits(Class cls, Class base)
 	return NO;
 }
 
+/**
+ * Free the instance variable lists associated with a class.
+ */
+void freeIvarLists(Class aClass);
+/**
+ * Free the method lists associated with a class.
+ */
+void freeMethodLists(Class aClass);
+
 #endif //__OBJC_CLASS_H_INCLUDED

runtime.c

@@ -622,7 +622,7 @@ id objc_getRequiredClass(const char *name)
 	return cls;
 }
 
-static void freeMethodLists(Class aClass)
+PRIVATE void freeMethodLists(Class aClass)
 {
 	struct objc_method_list *methods = aClass->methods;
 	while(methods != NULL)
@@ -637,7 +637,7 @@ static void freeMethodLists(Class aClass)
 	}
 }
 
-static void freeIvarLists(Class aClass)
+PRIVATE void freeIvarLists(Class aClass)
 {
 	struct objc_ivar_list *ivarlist = aClass->ivars;
 	if (NULL == ivarlist) { return; }