[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-ppc64-aix` running on `aix-ppc64` while building `clang` at step 3 "clean-build-dir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/64/builds/1436

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

```
Step 3 (clean-build-dir) failure: Delete failed. (failure) (timed out)
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: ClangScanDeps/verbose.test' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: rm -rf /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp
+ rm -rf /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp
RUN: at line 2: split-file /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/verbose.test /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp
+ split-file /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/verbose.test /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp
RUN: at line 3: sed -e "s|DIR|/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp|g" /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp/cdb.json.in > /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp/cdb.json
+ sed -e 's|DIR|/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp|g' /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp/cdb.json.in
RUN: at line 5: /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/bin/clang-scan-deps -compilation-database /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp/cdb.json -v -o /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp/result.json 2>&1 | /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/bin/FileCheck /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/verbose.test
+ /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/bin/clang-scan-deps -compilation-database /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp/cdb.json -v -o /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/test/ClangScanDeps/Output/verbose.test.tmp/result.json
+ /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/bin/FileCheck /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/verbose.test
/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/verbose.test:6:11: error: CHECK: expected string not found in input
// CHECK: *** Virtual File System Stats:
          ^
<stdin>:1:1: note: scanning from here
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
^
<stdin>:1:8: note: possible intended match here
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
       ^

Input file: <stdin>
Check file: /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/ClangScanDeps/verbose.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           1: PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace. 
check:6'0     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
check:6'1            ?                                                                                                     possible intended match
>>>>>>

--

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


```

</details>

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