[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 `llvm-clang-aarch64-darwin` running on `doug-worker-5` while building `clang,llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/28458

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM-Unit :: Support/./SupportTests/9/13' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/unittests/Support/./SupportTests-LLVM-Unit-67681-9-13.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=13 GTEST_SHARD_INDEX=9 /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/unittests/Support/./SupportTests
--


Note: This is test shard 10 of 13.
[==========] Running 127 tests from 88 test suites.
[----------] Global test environment set-up.
[----------] 2 tests from AlignmentTest
[ RUN      ] AlignmentTest.AlignOfConstant
[       OK ] AlignmentTest.AlignOfConstant (0 ms)
[ RUN      ] AlignmentTest.isAligned_isAddrAligned
[       OK ] AlignmentTest.isAligned_isAddrAligned (0 ms)
[----------] 2 tests from AlignmentTest (0 ms total)

[----------] 1 test from AllocatorTest
[ RUN      ] AllocatorTest.TestFasterSlabGrowthDelay
[       OK ] AllocatorTest.TestFasterSlabGrowthDelay (0 ms)
[----------] 1 test from AllocatorTest (0 ms total)

[----------] 1 test from MVEBuildAttr
[ RUN      ] MVEBuildAttr.testBuildAttr
[       OK ] MVEBuildAttr.testBuildAttr (0 ms)
[----------] 1 test from MVEBuildAttr (0 ms total)

[----------] 1 test from AlignNeededBuildAttr
[ RUN      ] AlignNeededBuildAttr.testBuildAttr
[       OK ] AlignNeededBuildAttr.testBuildAttr (0 ms)
[----------] 1 test from AlignNeededBuildAttr (0 ms total)

[----------] 1 test from Base64Test
[ RUN      ] Base64Test.Base64
[       OK ] Base64Test.Base64 (0 ms)
[----------] 1 test from Base64Test (0 ms total)

[----------] 1 test from BinaryStreamTest
[ RUN      ] BinaryStreamTest.StreamReaderIntegerArray
[       OK ] BinaryStreamTest.StreamReaderIntegerArray (0 ms)
[----------] 1 test from BinaryStreamTest (0 ms total)

[----------] 1 test from BLAKE3Test
[ RUN      ] BLAKE3Test.SmallerHashSize
[       OK ] BLAKE3Test.SmallerHashSize (0 ms)
[----------] 1 test from BLAKE3Test (0 ms total)

[----------] 1 test from BalancedPartitioningTest
[ RUN      ] BalancedPartitioningTest.MoveGain
[       OK ] BalancedPartitioningTest.MoveGain (0 ms)
...

```

</details>

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