[clang] [llvm] [LLVM] Add GNU make jobserver support (PR #145131)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-with-lto-ubuntu` running on `as-worker-91` while building `clang,llvm` at step 7 "test-stage1-compiler".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/49/builds/2341

<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-91/clang-with-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:530: note: using ld64.lld: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/bin/ld64.lld
llvm-lit: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:530: note: using wasm-ld: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/bin/wasm-ld
llvm-lit: /home/buildbot/as-worker-91/clang-with-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-91/clang-with-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:530: note: using ld.lld: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/bin/ld.lld
llvm-lit: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:530: note: using lld-link: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/bin/lld-link
llvm-lit: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:530: note: using ld64.lld: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/bin/ld64.lld
llvm-lit: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/llvm-project/llvm/utils/lit/lit/llvm/config.py:530: note: using wasm-ld: /home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/bin/wasm-ld
-- Testing: 87737 tests, 72 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90
FAIL: LLVM-Unit :: Support/./SupportTests/40/102 (84226 of 87737)
******************** TEST 'LLVM-Unit :: Support/./SupportTests/40/102' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/unittests/Support/./SupportTests-LLVM-Unit-1483694-40-102.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=102 GTEST_SHARD_INDEX=40 /home/buildbot/as-worker-91/clang-with-lto-ubuntu/build/stage1/unittests/Support/./SupportTests
--


Note: This is test shard 41 of 102.
[==========] Running 16 tests from 16 test suites.
[----------] Global test environment set-up.
[----------] 1 test from FPArchBuildAttr
[ RUN      ] FPArchBuildAttr.testBuildAttr
[       OK ] FPArchBuildAttr.testBuildAttr (0 ms)
[----------] 1 test from FPArchBuildAttr (0 ms total)

[----------] 1 test from CastingTest
[ RUN      ] CastingTest.isa_check_predicates
Classof: 0x55c823072ff8
Classof: 0x55c823072ff8
Classof: 0x55c823072ff8
Classof: 0x55c823072ff8
Classof: 0x55c823072ff8
Classof: 0x55c823072ff8
Classof: 0x55c823072ff8
[       OK ] CastingTest.isa_check_predicates (0 ms)
[----------] 1 test from CastingTest (0 ms total)

[----------] 1 test from ConverterEBCDIC
[ RUN      ] ConverterEBCDIC.convertToEBCDIC
[       OK ] ConverterEBCDIC.convertToEBCDIC (0 ms)
[----------] 1 test from ConverterEBCDIC (0 ms total)

[----------] 1 test from Error
[ RUN      ] Error.ErrorCodeConversions
[       OK ] Error.ErrorCodeConversions (0 ms)
[----------] 1 test from Error (0 ms total)

[----------] 1 test from HashBuilderTest/1, where TypeParam = <type>

```

</details>

https://github.com/llvm/llvm-project/pull/145131