Prep for update to latest QEMU version

tools/trusted_cross_toolchains/qemu_tool_arm.sh

 #!/bin/bash
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 set -o nounset
 set -o errexit
 
 #@ Various commands to emulate arm code using qemu
 #@
 #@ Note: this script is not meant to be run as
 #@     tools/trusted_cross_toolchains/qemu_tool_arm.sh
 #@ but rather as:
 #@     toolchain/linux_x86/arm_trusted/qemu_tool_arm.sh
 
-# From a qemu build based on qemu-0.10.1.tar.gz
 readonly SDK_ROOT=$(dirname $0)
 readonly QEMU=${SDK_ROOT}/qemu-arm
 readonly QEMU_STOCK=/usr/bin/qemu-arm
 readonly QEMU_JAIL=${SDK_ROOT}
 
 # Hook for adding stuff like timeout wrappers
 readonly QEMU_PREFIX_HOOK=${QEMU_PREFIX_HOOK:-}
 
 # NOTE: some useful debugging options for qemu:
 #       env vars:
@@ skipping 100 matching lines @@
   Usage
   exit -1
 elif [[ "$(type -t $1)" != "function" ]]; then
   echo "ERROR: unknown function '$1'." >&2
   echo "For help, try:"
   echo "    $0 help"
   exit 1
 else
   "$@"
 fi