Add rudimentary aix64-gcc target [from HEAD].

Submitted by: Stefan Neis

Configure

@@ -404,6 +404,7 @@ my %table=(
 #### IBM's AIX.
 "aix3-cc",  "cc:-O -DB_ENDIAN -qmaxmem=16384::(unknown):AIX::BN_LLONG RC4_CHAR:::",
 "aix-gcc",  "gcc:-O -DB_ENDIAN::-D_THREAD_SAFE:AIX::BN_LLONG RC4_CHAR::aix_ppc32.o::::::::::dlfcn:",
+"aix64-gcc","gcc:-O -DB_ENDIAN::-D_THREAD_SAFE:AIX::SIXTY_FOUR_BIT_LONG RC4_CHAR::aix_ppc64.o::::::::::dlfcn::::::-X64",
 # Below targets assume AIX 5. Idea is to effectively disregard $OBJECT_MODE
 # at build time. $OBJECT_MODE is respected at ./config stage!
 "aix-cc",   "cc:-q32 -O -DB_ENDIAN -qmaxmem=16384::-qthreaded:AIX::BN_LLONG RC4_CHAR::aix_ppc32.o::::::::::dlfcn:aix-shared::-q32:.so.\$(SHLIB_MAJOR).\$(SHLIB_MINOR)::-X 32",

TABLE

@@ -783,6 +783,33 @@ $shared_extension = .so.$(SHLIB_MAJOR).$(SHLIB_MINOR)
 $ranlib       = 
 $arflags      = -X 64
 
+*** aix64-gcc
+$cc           = gcc
+$cflags       = -O -DB_ENDIAN
+$unistd       = 
+$thread_cflag = -D_THREAD_SAFE
+$sys_id       = AIX
+$lflags       = 
+$bn_ops       = SIXTY_FOUR_BIT_LONG RC4_CHAR
+$cpuid_obj    = 
+$bn_obj       = aix_ppc64.o
+$des_obj      = 
+$aes_obj      = 
+$bf_obj       = 
+$md5_obj      = 
+$sha1_obj     = 
+$cast_obj     = 
+$rc4_obj      = 
+$rmd160_obj   = 
+$rc5_obj      = 
+$dso_scheme   = dlfcn
+$shared_target= 
+$shared_cflag = 
+$shared_ldflag = 
+$shared_extension = 
+$ranlib       = 
+$arflags      = -X64
+
 *** aux3-gcc
 $cc           = gcc
 $cflags       = -O2 -DTERMIO