Make examples' shebang use target tcc bindir path

Use @BINDIR@ in shebang of examples to put the right path on the target
system. That is, use #!/usr/local/bin/tcc if tcc is installed in /usr/local/bin
and #!/usr/bin/tcc if tcc is installed in /usr/bin/tcc.

examples/ex4.c

@@ -1,26 +0,0 @@
-#!./tcc -run -L/usr/X11R6/lib -lX11
-#include <stdlib.h>
-#include <stdio.h>
-#include <X11/Xlib.h>
-
-/* Yes, TCC can use X11 too ! */
-
-int main(int argc, char **argv)
-{
-    Display *display;
-    Screen *screen;
-
-    display = XOpenDisplay("");
-    if (!display) {
-        fprintf(stderr, "Could not open X11 display\n");
-        exit(1);
-    }
-    printf("X11 display opened.\n");
-    screen = XScreenOfDisplay(display, 0);
-    printf("width = %d\nheight = %d\ndepth = %d\n",
-           screen->width,
-           screen->height,
-           screen->root_depth);
-    XCloseDisplay(display);
-    return 0;
-}