Fix invalid-noreturn error

arch/aarch64.c

@@ -9,6 +9,7 @@ void exit(int8_t status){
         : "r" ((long)status)         // Input operand: status
         : "x0", "x8"           // Clobbered registers
   );
+  for (;;);
 }
 
 intptr_t write(int32_t fd, const void* buf, intptr_t size){

arch/mips.c

@@ -10,6 +10,7 @@ void exit(int8_t status){
     : "r" (status)
     : "a0", "v0"
   );
+  for(;;);
 }
 
 intptr_t write(int32_t fd, const void* buf, intptr_t size){

arch/x86_64.c

@@ -9,6 +9,7 @@ void exit(int8_t status) {
     : "a"(SYS_EXIT), "D"(status)
     :
   );
+  for(;;);
 }
 
 #define SYS_WRITE 1