Defines starting with `r' in src/cpu

• random src/cpu/sysdeps.h:155
• read src/cpu/sysdeps.h:388
• readdir src/cpu/sysdeps.h:371
• REGPARAM src/cpu/compat.h:26
• REGPARAM2 src/cpu/compat.h:30
• REGPARAM3 src/cpu/compat.h:34
• rename src/cpu/sysdeps.h:405
• RESTORE_EXCEPTION src/cpu/mmu_common.h:15
• RETROPLATFORM src/cpu/sysconfig.h:73
• RETSIGTYPE src/cpu/sysconfig.h:124
• rmdir src/cpu/sysdeps.h:399
• R_OK src/cpu/sysdeps.h:334