[llvm] [AArch64] Add SME peephole optimizer pass (PR #104612)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-sve-vls-2stage` running on `linaro-g3-01` while building `llvm` at step 18 "test-suite".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/4/builds/1489

Here is the relevant piece of the build log for the reference:
```
Step 18 (test-suite) failure: test (failure)
******************** TEST 'test-suite :: Fortran/gfortran/regression/gfortran-regression-execute-regression__random_init_2_f90.test' FAILED ********************

/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/tools/timeit-target --timeout 7200 --limit-core 0 --limit-cpu 7200 --limit-file-size 209715200 --limit-rss-size 838860800 --redirect-input /dev/null --chdir /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/Fortran/gfortran/regression/gfortran-regression-execute-regression__random_init_2_f90.wd --summary /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/Fortran/gfortran/regression/Output/gfortran-regression-execute-regression__random_init_2_f90.test.time /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/Fortran/gfortran/regression/gfortran-regression-execute-regression__random_init_2_f90

+ /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/tools/timeit-target --timeout 7200 --limit-core 0 --limit-cpu 7200 --limit-file-size 209715200 --limit-rss-size 838860800 --redirect-input /dev/null --chdir /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/Fortran/gfortran/regression/gfortran-regression-execute-regression__random_init_2_f90.wd --summary /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/Fortran/gfortran/regression/Output/gfortran-regression-execute-regression__random_init_2_f90.test.time /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/Fortran/gfortran/regression/gfortran-regression-execute-regression__random_init_2_f90
/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/test/sandbox/build/tools/timeit-target: error: child terminated by signal 6

********************


```

https://github.com/llvm/llvm-project/pull/104612