Remove more unused code.

advent.h

@@ -86,7 +86,6 @@ extern lcg_state lcgstate;
 /* b is not needed for POSIX but harmless */
 #define READ_MODE "rb"
 #define WRITE_MODE "wb"
-extern void* xmalloc(size_t);
 extern char* xstrdup(const char*);
 extern void packed_to_token(long, char token[6]);
 extern void newspeak(char*);

misc.c

@@ -10,17 +10,6 @@
 #include "linenoise/linenoise.h"
 #include "newdb.h"
 
-void* xmalloc(size_t size)
-{
-  void* ptr = malloc(size);
-  if (ptr == NULL)
-    {
-      fprintf(stderr, "Out of memory!\n");
-      exit(EXIT_FAILURE);
-    }
-  return(ptr);
-}
-
 char* xstrdup(const char* s)
 {
   char* ptr = strdup(s);