Re: Fix class type lookup from OBJ_TYPE_REF

[David Edelsohn]

This patch causes an ICE when building libobjc, which is part of
normal bootstrap.

PR 58179

/nasfarm/edelsohn/src/src/libobjc/accessors.m: In function 'objc_getProperty':
/nasfarm/edelsohn/src/src/libobjc/accessors.m:127:11: internal
compiler error: in obj_type_ref_class, at tree.c:11876
    result = RETAIN (*(pointer_to_ivar));

- David