tests: link them dynamically by default

. so that functionality is tested
	. add test63 that actually tests dlopen(), dlsym(),
	  etc. functionality; only built if clang supports it
	. also test10 test to copy more of the executable

test/test63.c

@@ -0,0 +1,58 @@
+
+/* Code to test runtime linking functionality.
+ * Load a shared object at runtime and verify that arguments passed to
+ * and from a function that is dynamically looked up make sense.
+ * This tests that (a) dynamic linking works at all (otherwise all the dl*
+ * functions don't work) and (b) the dynamic loading functionality works
+ * and (c) the PLT is sane and calling convention makes sense.
+ *
+ * We have to pass an absolute path to dlopen() for which we rely on 
+ * the test run script.
+ *
+ * The module we load is in mod.c.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <dlfcn.h>
+
+#define MAX_ERROR 2
+
+#include "magic.h"
+#include "common.c"
+
+int main (int argc, char *argv[])
+{
+  void *dlhandle;
+  long (*modf) (long, long *, long);
+  long v, *cookie = NULL, cookie2 = 0;
+  
+  start(63);
+
+  if(argc != 2) {
+	fprintf(stderr, "Usage: %s <module>\n", argv[0]);
+	exit(1);
+  }
+
+  if(!(dlhandle = dlopen(argv[1], RTLD_LAZY))) e(1);
+
+  if(!(modf = dlsym(dlhandle, "modfunction"))) e(2);
+  if(!(cookie = (long *) dlsym(dlhandle, "cookie"))) e(3);
+
+  if(*cookie == MAGIC2) { fprintf(stderr, "cookie already set\n"); e(4); }
+  if(cookie2 == MAGIC3) { fprintf(stderr, "cookie2 already set\n"); e(5); }
+
+  v = modf(MAGIC4, &cookie2, MAGIC5);
+
+  if(v != MAGIC1) { fprintf(stderr, "return value wrong\n"); e(9); }
+  if(*cookie != MAGIC2) { fprintf(stderr, "cookie set wrongly\n"); e(6); }
+  if(cookie2 != MAGIC3) { fprintf(stderr, "cookie2 set wrongly\n"); e(7); }
+
+  dlclose(dlhandle);
+
+  if(v != MAGIC1) { fprintf(stderr, "wrong return value.\n"); e(8); }
+
+  quit();
+
+  return(0);
+}