[llvm] [TLI] Add support for the `tgamma` libcall. (PR #113791)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-darwin` running on `doug-worker-3` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/23/builds/4254

<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 'Clang-Unit :: libclang/./libclangTests/11/14' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/unittests/libclang/./libclangTests-Clang-Unit-12944-11-14.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=14 GTEST_SHARD_INDEX=11 /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/unittests/libclang/./libclangTests
--

Script:
--
/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/unittests/libclang/./libclangTests --gtest_filter=LibclangParseTest.UnaryOperator
--
/Users/buildbot/buildbot-root/x86_64-darwin/llvm-project/clang/unittests/libclang/TestUtils.h:39: Failure
Value of: llvm::sys::fs::createUniqueDirectory("libclang-test", Dir)
  Actual: true
Expected: false

/Users/buildbot/buildbot-root/x86_64-darwin/llvm-project/clang/unittests/libclang/TestUtils.h:56: Failure
Value of: fs::remove(TestDir, false)
  Actual: true
Expected: false


/Users/buildbot/buildbot-root/x86_64-darwin/llvm-project/clang/unittests/libclang/TestUtils.h:39
Value of: llvm::sys::fs::createUniqueDirectory("libclang-test", Dir)
  Actual: true
Expected: false

/Users/buildbot/buildbot-root/x86_64-darwin/llvm-project/clang/unittests/libclang/TestUtils.h:56
Value of: fs::remove(TestDir, false)
  Actual: true
Expected: false


Script:
--
/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/unittests/libclang/./libclangTests --gtest_filter=LibclangStoreInMemoryEmptyPreambleStoragePathTest.CountPreambles
--
/Users/buildbot/buildbot-root/x86_64-darwin/llvm-project/clang/unittests/libclang/TestUtils.h:39: Failure
Value of: llvm::sys::fs::createUniqueDirectory("libclang-test", Dir)
  Actual: true
Expected: false

/Users/buildbot/buildbot-root/x86_64-darwin/llvm-project/clang/unittests/libclang/TestUtils.h:56: Failure
Value of: fs::remove(TestDir, false)
  Actual: true
Expected: false


/Users/buildbot/buildbot-root/x86_64-darwin/llvm-project/clang/unittests/libclang/TestUtils.h:39
Value of: llvm::sys::fs::createUniqueDirectory("libclang-test", Dir)
  Actual: true
...

```

</details>

https://github.com/llvm/llvm-project/pull/113791