[Build][OpenMP] Enable OpenMP library compilation. · Pull Request !630 · OpenHarmony/third_party_llvm-project

### Issue
https://gitee.com/openharmony/third_party_llvm-project/issues/IB4NCH?from=project-issue

### Reason (Purpose, Solved Problem)
Enable OpenMP for the llvm tool chain to meet developers' requirements.

### Description

1. Enable the compilation of both static and dynamic libraries for libomp.
2. Disable the use of shm_open on OHOS, because normal users do not have the permission to use shm_open function on OHOS.
3. Modify the lit scripts and lit.cfg within OpenMP to support running OpenMP test suites on remote devices.

### Test (Local test)
#### 1. Build test
By changing the build.py, now libomp.so and libomp.a can be generated while llvm building. Additionally, the compilation of the libomptarget-related libraries has been disabled.
![build result](https://foruda.gitee.com/images/1732958992128113476/efb329ee_8931596.png "屏幕截图")
#### 2. libomp.so use test
To test the function of the libomp library, I built a Dev Eco native project and called the openmp interface. The test result shows that the libomp library functions properly.
* Native project code
```c++
static void Test1()
{
    OH_LOG_INFO(LOG_APP, "=================Hello OpenMP test.====================");
    #pragma omp parallel
    {
        OH_LOG_INFO(LOG_APP, "Hello OpenMP!");
    }
}
```
* Result
![输入图片说明](https://foruda.gitee.com/images/1732958086272567503/62783c4c_8931596.png "屏幕截图")
#### 3. LLVM-lit OpenMP test suite
* Test shell script（Test cases related to libarcher (need tsan) and ompt (need libomptarget) are excluded.）
```sh
#!/bin/bash

DEVICE_COMPILE_FLAGS="--target=aarch64-linux-ohos  --sysroot=/home/workspace/llvm_omp/out-ompaso/sysroot -v -fstack-protector-strong -ffunction-sections -fdata-sections  -D__MUSL__"
TARGET_TRIPLE="aarch64-linux-ohos"
DEVICE_LINKER_FLAGS=
TOOLCHAIN_BIN_PATH="/home/workspace/llvm_omp/out-ompaso/llvm-install/bin"
CMAKE_BIN_PATH="/home/workspace/llvm_omp/prebuilts/cmake/linux-x86/bin"
CMAKE_SOURCE_PATH="/home/workspace/llvm_omp/toolchain/llvm-project/openmp"
CMAKE_TARGET_PATH="/home/workspace/llvm_omp/toolchain/omp_test/test"
OMP_LIB_PATH="/home/workspace/llvm_omp/out-ompaso/llvm-install/lib/aarch64-linux-ohos/libomp.so"

rm -r ${CMAKE_TARGET_PATH}/*
${CMAKE_BIN_PATH}/cmake -G Ninja ${CMAKE_SOURCE_PATH}/   \
            -B ${CMAKE_TARGET_PATH} \
            -DCMAKE_SYSTEM_NAME=OHOS \
            -DOHOS=ON \
            -DCMAKE_AR="${TOOLCHAIN_BIN_PATH}/llvm-ar" \
            -DCMAKE_C_COMPILER="${TOOLCHAIN_BIN_PATH}/clang" \
            -DOPENMP_ENABLE_LIBOMPTARGET="FALSE"  \
            -DCMAKE_CXX_COMPILER="${TOOLCHAIN_BIN_PATH}/clang++" \
            -DLLVM_TARGETS_TO_BUILD=AArch64 \
            -DOPENMP_LLVM_TOOLS_DIR="/home/workspace/llvm_omp/out-ompaso/llvm_make/bin" \
            -DOPENMP_LLVM_LIT_EXECUTABLE="/home/workspace/llvm_omp/out-ompaso/llvm_make/bin/llvm-lit" \
            -DCMAKE_C_COMPILER_TARGET="aarch64-linux-ohos" \
            -DCMAKE_CXX_COMPILER_TARGET="aarch64-linux-ohos" \
            -DCMAKE_CXX_FLAGS="${DEVICE_COMPILE_FLAGS}" \
            -DCMAKE_C_FLAGS="${DEVICE_COMPILE_FLAGS}" \
            -DCMAKE_EXE_LINKER_FLAGS="${DEVICE_LINKER_FLAGS}" \
            -DCMAKE_ASM_FLAGS="${DEVICE_COMPILE_FLAGS}" \
            -DCMAKE_ASM_COMPILER_TARGET="${TARGET_TRIPLE}" \
            -DCMAKE_BUILD_TYPE=Release

export HDC="/home/bin/HDC_BIN/hdc"
export HDC_SERVER="xxx.xxx.xxx.xxx:xxxx"
export HDC_TARGET_SERIAL="xxxxxxxxxxxx"
export LIB_PATH_ON_TARGET="/data/local/temp/lib"

# Push libomp.so to device
$HDC -s $HDC_SERVER -t $HDC_TARGET_SERIAL file send ${OMP_LIB_PATH} $LIB_PATH_ON_TARGET/

LOG_DATE=$(date +%Y%m%d_%H%M%S)
cd ${CMAKE_TARGET_PATH}

export LIT_FILTER_OUT="ompt/*|libarcher/*"
# export LIT_FILTER="affinity/format/simple_env.c"
ninja check-openmp | tee ${CMAKE_TARGET_PATH}/../check-openmp${LOG_DATE}.log
```
* Test result
![输入图片说明](https://foruda.gitee.com/images/1732957376450566933/1db5df9d_8931596.png "屏幕截图")
### Need to cherry-pick to release (eg：monthly_20221018, OpenHarmony-3.2-Beta5 ...) branch？

- [ ] yes，branch list:
- [x] no

why:

###  Compatibility impact assessment, please indicate (Y/N)

类型	指派人员	状态
审查	hhj 已审查通过 Pavel Kosov	已完成 (1/1人)
测试	openharmony_ci 已测试通过	已完成 (1/1人)

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