Update build scripts and documents of workload samples for wasi-sdk-12.0 (#484)

Update the build scripts of sample workloads (meshoptimizer/bwa/wasm-av1) to use the wasi-sdk-12.0 firstly to build the workload and discard clang-11, as wasi-sdk-12 supports wasi, simd and pthread better. And update the related documents.
Also modify wasm mini loader to sync up with the change of wasm normal loader.

Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>

samples/workload/bwa/CMakeLists.bwa_wasm.txt

@@ -102,6 +102,7 @@ target_compile_options(${PROJECT_NAME}
   PRIVATE
     -Wno-unused-function
     -Wno-unused-variable
+    -msimd128
 )
 
 target_link_options(${PROJECT_NAME}

samples/workload/bwa/CMakeLists.txt

@@ -5,6 +5,38 @@ cmake_minimum_required (VERSION 3.0)
 
 project(bwa_wasm)
 
+################  WASI-SDK ################
+find_path(WASI_SDK_HOME
+  NAMES wasi-sdk
+  PATHS /opt/
+  REQUIRED
+)
+
+if (NOT WASI_SDK_HOME)
+  message(FATAL_ERROR
+    "can not find wasi-sdk. "
+    "please download it from "
+    "https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-12/wasi-sdk-12.0-linux.tar.gz "
+    "and install it under /opt/wasi-sdk"
+  )
+endif()
+
+#
+# check clang version
+execute_process(COMMAND
+  ${WASI_SDK_HOME}/wasi-sdk/bin/clang --version
+  OUTPUT_VARIABLE clang_full_version_string
+)
+string(REGEX REPLACE ".*clang version ([0-9]+\\.[0-9]+).*" "\\1"
+  CLANG_VERSION_STRING ${clang_full_version_string}
+)
+message("cur clang version is ${CLANG_VERSION_STRING}")
+if(CLANG_VERSION_STRING VERSION_LESS 11.0)
+  message(FATAL_ERROR
+    "please install latest wai-sdk to get a clang-11 at least"
+  )
+endif()
+
 ################  EMCC ################
 if(NOT DEFINED ENV{EMSDK})
   message(FATAL_ERROR
@@ -85,7 +117,10 @@ ExternalProject_Add(bwa
   UPDATE_COMMAND git clean -fd && git checkout -- *
                   && ${CMAKE_COMMAND} -E echo "Copying pre-installed CMakeLists.txt"
                   && ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.bwa_wasm.txt CMakeLists.txt
-  CONFIGURE_COMMAND  ${CMAKE_COMMAND} -DCMAKE_TOOLCHAIN_FILE=${CMAKE_CURRENT_SOURCE_DIR}/../cmake/toolchain.cmake ${CMAKE_CURRENT_SOURCE_DIR}/bwa
+  CONFIGURE_COMMAND  ${CMAKE_COMMAND}
+                         -DWASI_SDK_PREFIX=${WASI_SDK_HOME}/wasi-sdk
+                         -DCMAKE_TOOLCHAIN_FILE=${WASI_SDK_HOME}/wasi-sdk/share/cmake/wasi-sdk.cmake
+                         ${CMAKE_CURRENT_SOURCE_DIR}/bwa
   BUILD_COMMAND  make bwa_wasm_opt
   INSTALL_COMMAND ${CMAKE_COMMAND} -E copy ./bwa.opt.wasm ${CMAKE_CURRENT_SOURCE_DIR}/build/bwa.wasm
 )

samples/workload/bwa/README.md

@@ -40,8 +40,7 @@ $ make
 Then compile wasm file to aot file and run:
 
 ``` shell
-$ cd <wamr dir>/wamr-compiler/build
-$ ./wamrc --enable-simd -o bwa.aot ./bwa.wasm
-$ cd <wamr dir>/product-mini/platforms/linux/
-$ ./iwasm --dir=. ./bwa.aot index hs38DH.fa
+$ cd <wamr dir>/samples/workload/bwa/build
+$ <wamr dir>/wamr-compiler/build/wamrc --enable-simd -o bwa.aot bwa.wasm
+$ <wamr dir>/product-mini/platforms/linux/iwasm --dir=. bwa.aot index hs38DH.fa
 ```