Rationalised use of #includes to be more standards-compliant.

lang/pc/comp/input.c

@@ -1,5 +1,8 @@
 /* I N S T A N T I A T I O N   O F   I N P U T   P A C K A G E */
 
+#include    <stdlib.h>
+#include    <stdio.h>
+#include    <string.h>
 #include	"f_info.h"
 struct f_info	file_info;
 #include	"input.h"