Patch by Vladimir Marangozov, inspired by a bug report from Gary

Duzan, for AIX, to support C++ objects with static initializers, when
using the genuine IBM C++ compiler (namely xlC/xlC_r).

See accompanying patches to acconfig.h and importdl.c.

configure.in

@@ -543,6 +543,18 @@ AC_MSG_RESULT($LINKFORSHARED)
 # checks for libraries
 AC_CHECK_LIB(dl, dlopen)	# Dynamic linking for SunOS/Solaris and SYSV
 AC_CHECK_LIB(dld, shl_load)	# Dynamic linking for HP-UX
+
+# checks for system dependent C++ extensions support
+case "$ac_sys_system" in
+	AIX*)	AC_MSG_CHECKING(for genuine AIX C++ extensions support)
+		AC_TRY_LINK([#include "/usr/lpp/xlC/include/load.h"],
+			    [loadAndInit("", 0, "")],
+			    [AC_DEFINE(AIX_GENUINE_CPLUSPLUS)
+			     AC_MSG_RESULT(yes)],
+			    [AC_MSG_RESULT(no)]);;
+	*) ;;
+esac
+
 # Most SVR4 platforms (e.g. Solaris) need -lsocket and -lnsl.
 # However on SGI IRIX, these exist but are broken.
 # BeOS' sockets are stashed in libnet.