Defines starting with `u' in osfmk/ppc

• ubamr osfmk/ppc/asm.h:106
• UCHAR_MAX osfmk/ppc/machlimits.h:67
• UINT_MAX osfmk/ppc/machlimits.h:75
• ULONG_MAX osfmk/ppc/machlimits.h:79
• ummcr0 osfmk/ppc/asm.h:107
• ummcr1 osfmk/ppc/asm.h:111
• ummcr2 osfmk/ppc/asm.h:105
• UPDATE_PPC_EXCEPTION_STATE osfmk/ppc/trap.c:105
• upmc1 osfmk/ppc/asm.h:108
• upmc2 osfmk/ppc/asm.h:109
• upmc3 osfmk/ppc/asm.h:112
• upmc4 osfmk/ppc/asm.h:113
• usda osfmk/ppc/asm.h:114
• USE_EXTRA_REGS osfmk/ppc/net_filter.c:31
• USHRT_MAX osfmk/ppc/machlimits.h:71
• usia osfmk/ppc/asm.h:110
• USRSTACK osfmk/ppc/status.c:49