Don't abort when seeing the default CPU model/platform returned by
QEMU.

diff -ru -x '*~' gmp-5.0.4-orig/mpn/x86_64/fat/fat.c gmp-5.0.4/mpn/x86_64/fat/fat.c
--- gmp-5.0.4-orig/mpn/x86_64/fat/fat.c	2012-02-10 11:23:05.000000000 +0100
+++ gmp-5.0.4/mpn/x86_64/fat/fat.c	2012-04-01 21:38:35.843066724 +0200
@@ -194,13 +194,16 @@
     {
       switch (family)
 	{
+#if 0
 	case 4:
 	case 5:
 	  abort ();		/* 32-bit processors */
+#endif
 
 	case 6:
 	  switch (model)
 	    {
+#if 0
 	    case 0x00:
 	    case 0x01:
 	    case 0x02:
@@ -217,6 +220,7 @@
 	    case 0x0d:		/* Dothan */
 	    case 0x0e:		/* Yonah */
 	      abort ();		/* 32-bit processors */
+#endif
 
 	    case 0x0f:		/* Conroe Merom Kentsfield Allendale */
 	    case 0x10: