lang/mono5*: unbreak with kern.elf*.allow_wx=0

$ mono foo
Segmentation fault

* thread #1, name = 'mono-sgen', stop reason = signal SIGSEGV: invalid address (fault address: 0x0)
    frame #0: 0x00000000005632f9 mono`mono_arch_create_sdb_trampoline(single_step=0, info=0x0000000820fe7d90, aot=0) at tramp-amd64.c:854:2
   851          // IP saved at CFA - 8
   852          mono_add_unwind_op_offset (unwind_ops, code, buf, AMD64_RIP, -cfa_offset);
   853
-> 854          amd64_push_reg (code, AMD64_RBP);
   855          cfa_offset += sizeof(mgreg_t);
   856          mono_add_unwind_op_def_cfa_offset (unwind_ops, code, buf, cfa_offset);
   857          mono_add_unwind_op_offset (unwind_ops, code, buf, AMD64_RBP, - cfa_offset);
(lldb) bt
* thread #1, name = 'mono-sgen', stop reason = signal SIGSEGV: invalid address (fault address: 0x0)
  * frame #0: 0x00000000005632f9 mono`mono_arch_create_sdb_trampoline(single_step=0, info=0x0000000820fe7d90, aot=0) at tramp-amd64.c:854:2
    frame #1: 0x000000000047cf36 mono`mini_get_breakpoint_trampoline at mini-trampolines.c:1812:12
    frame #2: 0x00000000004dc5a1 mono`mono_arch_init at mini-amd64.c:1405:19
    frame #3: 0x000000000035fde4 mono`mini_init(filename="foo", runtime_version=0x0000000000000000) at mini-runtime.c:4364:2
    frame #4: 0x0000000000426853 mono`mono_main(argc=2, argv=0x0000000820fe8268) at driver.c:2470:11
    frame #5: 0x0000000000359363 mono`mono_main_with_options(argc=2, argv=0x0000000820fe8268) at main.c:50:9
    frame #6: 0x00000000003589b1 mono`main(argc=2, argv=0x0000000820fe8268) at main.c:406:9
    frame #7: 0x0000000000358770 mono`_start(ap=<unavailable>, cleanup=<unavailable>) at crt1_c.c:75:7