[MIPS] [MC] [CLANG] Use pc-relative relocations in .eh_frame · Pull Request !199 · OpenHarmony/third_party_llvm-project

### Issue

#I5WVZZ

### Reason (Purpose, Solved Problem)

according the issue mentioned above, lld has failed linking and reports "relocation R_MIPS_32 cannot be used against local symbol", when using `-fPIC` with `mipsel-linux-ohos` target option.

this PR will fix #I5WVZZ. we will not need use `-Wl,-z,notext` and `-no-pie` with this patch.

### Description

> Use pc-relative relocations in .eh_frame. R_MIPS_PC32 relocation is generated in 32-bit case. R_MIPS_PC32 | R_MIPS_64 relocation chain is generated in 64-bit case for all code model.
> 
> With this change object files can be linked by LLD without having to pass -Wl,-z,notext options.
> 
> For compatibility with tools unsupported 64-bit pc-relative relocations the patch introduces new command line options in Clang: mmips-pc64-rel and mno-mips-pc64-rel. These options passed to LLVM by Clang driver as -mips-pc64-rel={true|false}.

* _This PR comes from https://reviews.llvm.org/D80392, which has not merged into LLVM's trunk currently._ 
* and there is additional changes: remove `m` prefix for introduced parameters in llvm, following the [advice](https://reviews.llvm.org/D80392#inline-1032322) from a upstream maintainer, MaskRay.

### Test (Local test)
![testresult](https://foruda.gitee.com/images/1680586441869139937/f6d95808_11699370.png "屏幕截图")
run: `clang++ --target=mipsel-linux-ohos -march=mips32r2 -fPIC -L /root/oh-llvm/monorepo/out/lib/ -fuse-ld=lld --rtlib=compiler-rt -O3 -o a.out t.cpp m.cpp`
the used testcases is in the issue mentioned above.

### Need to cherry-pick to release (eg：monthly_20221018, OpenHarmony-3.2-Beta5 ...) branch？

- [ ] yes，branch list:
- [x] no

why:  `mipsel-linux-ohos` target isn't used by any devices/boards in OHOS's master branch.

类型	指派人员	状态
审查	hhj Pavel Kosov	进行中 (0/1人)
测试	openharmony_ci 已测试通过	已完成 (1/1人)

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