Add wrapper for prebuilt QEMU

Avoid having to set LD_LIBRARY_PATH in the Makefile by adding a wrapper
for prebuilt QEMU that handles it transparently to the caller.

Change-Id: I2a5623f5b50ffef3b3ae8d0dae3a83d8e2876d97
diff --git a/linux-x86/qemu/bin/qemu-system-aarch64.sh b/linux-x86/qemu/bin/qemu-system-aarch64.sh
new file mode 100755
index 0000000..488464f
--- /dev/null
+++ b/linux-x86/qemu/bin/qemu-system-aarch64.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+# Copyright 2020 The Android KVM Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Wrapper around prebuilt QEMU binary that sets LD_LIBRARY_PATH.
+
+BIN_DIR="$(dirname "${BASH_SOURCE[0]}")"
+LIB_DIR="${BIN_DIR}/../lib"
+BIN="${BIN_DIR}/qemu-system-aarch64"
+
+export LD_LIBRARY_PATH="${LIB_DIR}:${LD_LIBRARY_PATH:-}"
+exec "${BIN}" "$@"