[llvm] [InstCombine] Fold cttz(mul X, OddC) -> cttz(X) (PR #214376)

[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/21639

<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 :: ./AllClangUnitTests/5/54' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/unittests/./AllClangUnitTests-Clang-Unit-98432-5-54.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=54 GTEST_SHARD_INDEX=5 /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/unittests/./AllClangUnitTests
--

Note: This is test shard 6 of 54.
[==========] Running 504 tests from 102 test suites.
[----------] Global test environment set-up.
[----------] 1 test from MinimizeSourceToDependencyDirectivesTest
[ RUN      ] MinimizeSourceToDependencyDirectivesTest.EmptyHash
[       OK ] MinimizeSourceToDependencyDirectivesTest.EmptyHash (0 ms)
[----------] 1 test from MinimizeSourceToDependencyDirectivesTest (0 ms total)

[----------] 1 test from HeaderMapTest
[ RUN      ] HeaderMapTest.checkHeaderValidButEmpty
[       OK ] HeaderMapTest.checkHeaderValidButEmpty (0 ms)
[----------] 1 test from HeaderMapTest (0 ms total)

[----------] 1 test from LexHLSLRootSignatureTest
[ RUN      ] LexHLSLRootSignatureTest.ValidCaseInsensitiveKeywordsTest
[       OK ] LexHLSLRootSignatureTest.ValidCaseInsensitiveKeywordsTest (0 ms)
[----------] 1 test from LexHLSLRootSignatureTest (0 ms total)

[----------] 1 test from ParseHLSLRootSignatureTest
[ RUN      ] ParseHLSLRootSignatureTest.InvalidParseInvalidTokenTest
[       OK ] ParseHLSLRootSignatureTest.InvalidParseInvalidTokenTest (1 ms)
[----------] 1 test from ParseHLSLRootSignatureTest (1 ms total)

[----------] 1 test from EscapedCommandLineTest
[ RUN      ] EscapedCommandLineTest.ParseSingleArg
[       OK ] EscapedCommandLineTest.ParseSingleArg (0 ms)
[----------] 1 test from EscapedCommandLineTest (0 ms total)

[----------] 1 test from MultilibTest
[ RUN      ] MultilibTest.SetPushback
[       OK ] MultilibTest.SetPushback (0 ms)
[----------] 1 test from MultilibTest (0 ms total)

[----------] 1 test from CFG
[ RUN      ] CFG.RangeBasedForOverDependentType
[       OK ] CFG.RangeBasedForOverDependentType (16 ms)
[----------] 1 test from CFG (16 ms total)

[----------] 2 tests from ExprMutationAnalyzerTest
[ RUN      ] ExprMutationAnalyzerTest.NestedMemberModified
[       OK ] ExprMutationAnalyzerTest.NestedMemberModified (19 ms)
[ RUN      ] ExprMutationAnalyzerTest.PointeeMutatedByPointerArithmeticAdd
[       OK ] ExprMutationAnalyzerTest.PointeeMutatedByPointerArithmeticAdd (30 ms)
[----------] 2 tests from ExprMutationAnalyzerTest (50 ms total)
...

```

</details>

https://github.com/llvm/llvm-project/pull/214376