improve build_llvm.sh

Author: Septa2112

wamr-compiler/README.md

@@ -13,6 +13,7 @@ sudo apt-get install git build-essential cmake g++-multilib libgcc-9-dev lib32gc
 
 ```shell
 cd wamr-compiler
+# or explicitly with bash: bash ./build_llvm.sh
 ./build_llvm.sh (or "./build_llvm_xtensa.sh" to support xtensa target)
 mkdir build && cd build
 cmake .. (or "cmake .. -DWAMR_BUILD_PLATFORM=darwin" for MacOS)

wamr-compiler/build_llvm.sh

@@ -1,8 +1,10 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 # Copyright (C) 2020 Intel Corporation. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
+set -e
+
 TEMP_DIR=$(mktemp -d)
 
 cleanup() {