[clang] [llvm] [Clang-Repl] Add support for out-of-process execution. (PR #110418)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-with-thin-lto-ubuntu` running on `as-worker-92` while building `clang` at step 7 "test-stage1-compiler".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/127/builds/1404

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

```
Step 7 (test-stage1-compiler) failure: build (failure)
...
llvm-lit: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld64.lld: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/ld64.lld
llvm-lit: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using wasm-ld: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/wasm-ld
llvm-lit: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/utils/lit/tests/lit.cfg:111: warning: Setting a timeout per test not supported. Requires the Python psutil module but it could not be found. Try installing it via pip or via your operating system's package manager.
 Some tests will be skipped and the --timeout command line argument will not work.
llvm-lit: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld.lld: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/ld.lld
llvm-lit: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using lld-link: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/lld-link
llvm-lit: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using ld64.lld: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/ld64.lld
llvm-lit: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:506: note: using wasm-ld: /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/wasm-ld
-- Testing: 81948 tests, 72 workers --
Testing:  0.. 10
FAIL: Clang :: Interpreter/out-of-process.cpp (12594 of 81948)
******************** TEST 'Clang :: Interpreter/out-of-process.cpp' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
RUN: at line 3: cat /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/clang/test/Interpreter/out-of-process.cpp | /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/clang-repl -oop-executor -orc-runtime | /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/FileCheck /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/clang/test/Interpreter/out-of-process.cpp
+ cat /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/clang/test/Interpreter/out-of-process.cpp
+ /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/FileCheck /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/clang/test/Interpreter/out-of-process.cpp
+ /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/clang-repl -oop-executor -orc-runtime
clang-repl: No such file or directory
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/bin/FileCheck /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/llvm-project/clang/test/Interpreter/out-of-process.cpp

--

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 

1 warning(s) in tests
********************
Failed Tests (1):
  Clang :: Interpreter/out-of-process.cpp


Testing Time: 210.09s

Total Discovered Tests: 111470
  Skipped          :     24 (0.02%)
  Unsupported      :   2735 (2.45%)
  Passed           : 108526 (97.36%)
  Expectedly Failed:    184 (0.17%)
  Failed           :      1 (0.00%)
FAILED: CMakeFiles/check-all /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/CMakeFiles/check-all 
cd /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1 && /usr/bin/python3.10 /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/./bin/llvm-lit -sv --param USE_Z3_SOLVER=0 /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/utils/mlgo-utils /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/tools/lld/test /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/tools/clang/test /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/utils/lit /home/buildbot/as-worker-92/clang-with-thin-lto-ubuntu/build/stage1/test
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/110418