Use <stdlib.h> instead of declaring exit manualy.

Author: sunfishcode

libc-bottom-half/cloudlibc/src/include/stdlib.h

@@ -139,8 +139,8 @@ void *calloc(size_t, size_t);
 div_t div(int, int) __pure2;
 double drand48(void);
 double erand48(__uint16_t *);
-_Noreturn void exit(int);
 #endif
+_Noreturn void exit(int);
 void free(void *);
 #ifdef __wasilibc_unmodified_upstream
 char *getenv(const char *);

libc-bottom-half/crt/crt1.c

@@ -1,8 +1,8 @@
 #include <wasi/api.h>
+#include <stdlib.h>
 extern void __wasm_call_ctors(void);
 extern int __original_main(void);
 extern void __wasm_call_dtors(void);
-_Noreturn void exit(int);
 
 __attribute__((export_name("_start")))
 void _start(void) {