Enable 64-bit build on Snow Leopard


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@3911 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/jpeg/acinclude.m4 b/common/jpeg/acinclude.m4
index f7d7b69..9b8d312 100644
--- a/common/jpeg/acinclude.m4
+++ b/common/jpeg/acinclude.m4
@@ -44,7 +44,14 @@
     objfmt='ELF'
   ;;
   darwin* | rhapsody* | nextstep* | openstep* | macos*)
-    objfmt='Mach-O'
+    case "$host_cpu" in
+      x86_64)
+        objfmt='Mach-O64'
+        ;;
+      *)
+        objfmt='Mach-O'
+        ;;
+    esac
   ;;
   *)
     objfmt='ELF ?'
@@ -68,6 +75,7 @@
   ELF64)      NAFLAGS='-felf64 -DELF -D__x86_64__';;
   RDF)        NAFLAGS='-frdf -DRDF';;
   Mach-O)     NAFLAGS='-fmacho -DMACHO';;
+  Mach-O64)   NAFLAGS='-fmacho64 -DMACHO -D__x86_64__';;
 esac
 AC_MSG_RESULT([$NAFLAGS])
 AC_SUBST([NAFLAGS])