[gimp/gimp-2-6] No SYMPREFIX should be used for 64-bit Windows

[Tor Lillqvist <tml src gnome org>]

commit c54dff49f85d38a558aa621d2aa0c8808c23bab2
Author: Tor Lillqvist <tml iki fi>
Date:   Mon Sep 27 18:21:53 2010 +0300

    No SYMPREFIX should be used for 64-bit Windows
    
    Earlier builds of mingw-w64 misguidedly used the _ prefix, but not
    current ones. Thanks to Fridrich Strba.

 configure.in |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/configure.in b/configure.in
index 75f9b49..d35c329 100644
--- a/configure.in
+++ b/configure.in
@@ -841,7 +841,10 @@ AC_MSG_CHECKING([whether symbols are prefixed])
 
 case "$host_os" in
   mingw*)
-    SYMPREFIX='_'
+    case "$host_cpu" in 
+	  x86_64) SYMPREFIX='' ;;
+	  *) SYMPREFIX='_' ;;
+	esac
     ;;
   darwin* | rhapsody* | machten*)
     SYMPREFIX='_'