main/ruby: version 3.1.1 fails to build on riscv64
https://build.alpinelinux.org/buildlogs/build-edge-riscv64/main/ruby/ruby-3.1.1-r0.log:
vm_dump.c: In function 'rb_dump_machine_register':
vm_dump.c:916:45: error: 'REG_S1' undeclared (first use in this function); did you mean 'REG_S0'?
916 | dump_machine_register(mctx->__gregs[REG_S1], "s1");
| ^~~~~~
vm_dump.c:815:87: note: in definition of macro 'dump_machine_register'
815 | # define dump_machine_register(reg, regstr) (col_count = print_machine_register(reg, regstr, col_count, 80))
| ^~~
vm_dump.c:916:45: note: each undeclared identifier is reported only once for each function it appears in
916 | dump_machine_register(mctx->__gregs[REG_S1], "s1");
| ^~~~~~
vm_dump.c:815:87: note: in definition of macro 'dump_machine_register'
815 | # define dump_machine_register(reg, regstr) (col_count = print_machine_register(reg, regstr, col_count, 80))
| ^~~
vm_dump.c:925:45: error: 'REG_S2' undeclared (first use in this function); did you mean 'REG_S0'?
925 | dump_machine_register(mctx->__gregs[REG_S2], "s2");
| ^~~~~~
vm_dump.c:815:87: note: in definition of macro 'dump_machine_register'
815 | # define dump_machine_register(reg, regstr) (col_count = print_machine_register(reg, regstr, col_count, 80))
| ^~~