Build and pass all test cases on a multiprocessor HP-UX.

* configure.ac, check/Makefile.am, doc/Makefile.am: Do not
	explicitly link to -ldl, but instead autodetect the library
	with dlopen, dlsym, etc.

	* check/lightning.c: Add workaround to apparently buggy
	getopt in HP-UX that sets optind to the wrong index, and
	use RTLD_NEXT on HP-UX instead of RTLD_DEFAULT to dlsym
	global symbols.

	* include/lightning.h: Rework definitions of wordsize and
	byte order to detect proper values on HP-UX.

	* lib/lightning.c: Minor correction to use MAP_ANONYMOUS
	instead of MAP_ANON on HP-UX.

	* lib/jit_hppa.c: Float arguments must be passed on integer
	registers on HP-UX, not only for varargs functions.
	  Add code to properly clear instruction cache. This was
	not required on Debian hppa port, but may have been working
	by accident.

	* lib/jit_hppa-cpu.c: Follow pattern of HP-UX binaries and
	use bve,n instead of bv,n to return from functions.

	* lib/jit_hppa-fpu.c: For some reason "fst? frX,rX,(rY)" did
	not work on the tested computer	(HP-UX B.11.23 U 9000/785 HP-UX)
	so the code was changed, at first for __hpux only to add the
	base and offset register and use the instruction with an
	immediate (zero) offset.

lib/lightning.c

@@ -19,6 +19,10 @@
 #include <lightning/jit_private.h>
 #include <sys/mman.h>
 
+#ifndef MAP_ANON
+#  define MAP_ANON			MAP_ANONYMOUS
+#endif
+
 #define jit_regload_reload		0	/* convert to reload */
 #define jit_regload_delete		1	/* just remove node */
 #define jit_regload_isdead		2	/* delete and unset live bit */