Change to X64 default build in tool scripts in sdk/bin

sdk/bin/dart

 #!/bin/bash
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 function follow_links() {
   file="$1"
   while [ -h "$file" ]; do
     # On Mac OS, readlink -f doesn't work.
     file="$(readlink "$file")"
@@ skipping 11 matching lines @@
 then
   OUT_DIR="$CUR_DIR"/../../xcodebuild/
 else
   OUT_DIR="$CUR_DIR"/../../out/
 fi
 
 if [ -z "$DART_CONFIGURATION" ];
 then
   DIRS=$( ls "$OUT_DIR" )
   # list of possible configurations in decreasing desirability
-  CONFIGS=("ReleaseIA32" "ReleaseX64" "DebugIA32" "DebugX64"
+  CONFIGS=("ReleaseX64" "ReleaseIA32" "DebugX64" "DebugIA32"
     "ReleaseARM"    "ReleaseARM64"    "ReleaseARMV5TE"    "ReleaseMIPS"
     "DebugARM"      "DebugARM64"      "DebugARMV5TE"      "DebugMIPS")
   DART_CONFIGURATION="None"
   for CONFIG in ${CONFIGS[*]}
   do
     for DIR in $DIRS;
     do
       if [ "$CONFIG" = "$DIR" ];
       then
         # choose most desirable configuration that is available and break
         DART_CONFIGURATION="$DIR"
         break 2
       fi
     done
   done
   if [ "$DART_CONFIGURATION" = "None" ]
   then
     echo "No valid dart configuration found in $OUT_DIR"
     exit 1
   fi
 fi
 
 BIN_DIR="$OUT_DIR$DART_CONFIGURATION"
 
 exec "$BIN_DIR"/dart "$@"