Rename a function to avoid a clash with an em system call.

lang/basic/lib/file.c

@@ -123,7 +123,7 @@ int _ioeof(int channel)
 	return (0);
 }
 
-void _close(void)
+void _closeall(void)
 {
 	/* close all open files */
 	int i;

lang/basic/src/basic.g

@@ -207,7 +207,7 @@ clearstmt { int exp; }
 	;
 
 closestmt:	filelist		
-	|	/* empty */	{ C_cal("_close"); }
+	|	/* empty */	{ C_cal("_closeall"); }
 	;
 
 filelist { int intv; }