[llvm] [LoongArch] Implement Statepoint lowering (PR #108212)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-arm64-windows-msvc` running on `linaro-armv8-windows-msvc-04` while building `llvm` at step 5 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/161/builds/1994

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (ninja check 1) failure: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
...
UNSUPPORTED: mlgo-utils :: corpus/combine_training_corpus_script.test (83297 of 83307)
UNSUPPORTED: mlgo-utils :: corpus/combine_training_corpus_test.py (83298 of 83307)
UNSUPPORTED: mlgo-utils :: corpus/extract_ir_script.test (83299 of 83307)
UNSUPPORTED: mlgo-utils :: corpus/make_corpus_script.test (83300 of 83307)
UNSUPPORTED: mlgo-utils :: corpus/extract_ir_test.py (83301 of 83307)
UNSUPPORTED: mlgo-utils :: corpus/make_corpus_test.py (83302 of 83307)
UNSUPPORTED: mlgo-utils :: pytype.test (83303 of 83307)
PASS: lit :: selecting.py (83304 of 83307)
PASS: lit :: shtest-shell.py (83305 of 83307)
PASS: lit :: shtest-define.py (83306 of 83307)
command timed out: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
program finished with exit code 1
elapsedTime=3130.526610

```

</details>

https://github.com/llvm/llvm-project/pull/108212