Error was reported when building jetstream benchmark with emsdk:
```
clang: error: unsupported option '-msse2' for target 'wasm32-wasi'
```
Error was reported when building bwa workload:
```
fatal: reference is not a tree: 139f68fc4c3747813783a488aef2adc86626b01b
```
Upgrade the version of related toolkits:
- upgrade llvm to 15.0
- upgrade wasi-sdk to 19.0
- upgrade emsdk to 3.1.28
- upgrade wabt to 1.0.31
- upgrade binaryen to 111
And upgrade the CI scripts, sample workload build scripts, Dockerfiles, and documents.
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>
