Defines starting with `u' in machdep/ppc

• UnimpMQptr machdep/ppc/nkdefs.h:205
• UnimpMQtmp machdep/ppc/nkdefs.h:206
• UnimpRA machdep/ppc/nkdefs.h:203
• UnimpRB machdep/ppc/nkdefs.h:204
• UnimpRS machdep/ppc/nkdefs.h:201
• UnimpRSRT machdep/ppc/nkdefs.h:200
• UnimpRT machdep/ppc/nkdefs.h:202
• UnimpXERtmp machdep/ppc/nkdefs.h:207
• UPDATE_PPC_EXCEPTION_STATE machdep/ppc/trap.c:91
• USE_FAST_BCOPY machdep/ppc/bcopy.h:34
• USE_FLOATING_POINT_IN_KERNEL machdep/ppc/bcopy.s:79