LLVM PGO (Profile-Guided Optimization) allows the compiler to better optimize code
for how it actually runs. This PR implements the AOT static PGO, and is tested on
Linux x86-64 and x86-32. The basic steps are:
1. Use `wamrc --enable-llvm-pgo -o <aot_file_of_pgo> <wasm_file>`
to generate an instrumented aot file.
2. Compile iwasm with `cmake -DWAMR_BUILD_STATIC_PGO=1` and run
`iwasm --gen-prof-file=<raw_profile_file> <aot_file_of_pgo>`
to generate the raw profile file.
3. Run `llvm-profdata merge -output=<profile_file> <raw_profile_file>`
to merge the raw profile file into the profile file.
4. Run `wamrc --use-prof-file=<profile_file> -o <aot_file> <wasm_file>`
to generate the optimized aot file.
5. Run the optimized aot_file: `iwasm <aot_file>`.
The test scripts are also added for each benchmark, run `test_pgo.sh` under
each benchmark's folder to test the AOT static pgo.
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.
Enhance workflows by caching llvm directories directly instead of
caching the llvm-xxx.tar.gz packages, so as to reduce the time
consumption of unpacking the cached LLVM packages.
Implement the latest SIMD opcodes and update LLVM 13.0,
update the llvm build scripts, update the sample workloads‘ build scripts,
and build customized wasi-sdk to build some workloads.
Also refine the CI rules.
Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>