[clang] [clang-format] Allow specifying the language for `.h` files (PR #128122)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `sanitizer-x86_64-linux-android` running on `sanitizer-buildbot-android` while building `clang` at step 2 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/186/builds/6751

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

```
Step 2 (annotate) failure: 'python ../sanitizer_buildbot/sanitizers/zorg/buildbot/builders/sanitizers/buildbot_selector.py' (failure)
...
[       OK ] AddressSanitizer.AtoiAndFriendsOOBTest (2258 ms)
[ RUN      ] AddressSanitizer.HasFeatureAddressSanitizerTest
[       OK ] AddressSanitizer.HasFeatureAddressSanitizerTest (0 ms)
[ RUN      ] AddressSanitizer.CallocReturnsZeroMem
[       OK ] AddressSanitizer.CallocReturnsZeroMem (13 ms)
[ DISABLED ] AddressSanitizer.DISABLED_TSDTest
[ RUN      ] AddressSanitizer.IgnoreTest
[       OK ] AddressSanitizer.IgnoreTest (0 ms)
[ RUN      ] AddressSanitizer.SignalTest
[       OK ] AddressSanitizer.SignalTest (210 ms)
[ RUN      ] AddressSanitizer.ReallocTest
[       OK ] AddressSanitizer.ReallocTest (30 ms)
[ RUN      ] AddressSanitizer.WrongFreeTest
[       OK ] AddressSanitizer.WrongFreeTest (134 ms)
[ RUN      ] AddressSanitizer.LongJmpTest
[       OK ] AddressSanitizer.LongJmpTest (0 ms)
[ RUN      ] AddressSanitizer.ThreadStackReuseTest
[       OK ] AddressSanitizer.ThreadStackReuseTest (11 ms)
[ DISABLED ] AddressSanitizer.DISABLED_MemIntrinsicUnalignedAccessTest
[ DISABLED ] AddressSanitizer.DISABLED_LargeFunctionSymbolizeTest
[ DISABLED ] AddressSanitizer.DISABLED_MallocFreeUnwindAndSymbolizeTest
[ RUN      ] AddressSanitizer.UseThenFreeThenUseTest
[       OK ] AddressSanitizer.UseThenFreeThenUseTest (122 ms)
[ RUN      ] AddressSanitizer.FileNameInGlobalReportTest
[       OK ] AddressSanitizer.FileNameInGlobalReportTest (113 ms)
[ DISABLED ] AddressSanitizer.DISABLED_StressStackReuseAndExceptionsTest
[ RUN      ] AddressSanitizer.MlockTest
[       OK ] AddressSanitizer.MlockTest (0 ms)
[ DISABLED ] AddressSanitizer.DISABLED_DemoThreadedTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoStackTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoThreadStackTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFLowIn
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFLowLeft
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFLowRight
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFHigh
[ DISABLED ] AddressSanitizer.DISABLED_DemoOOM
[ DISABLED ] AddressSanitizer.DISABLED_DemoDoubleFreeTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoNullDerefTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoFunctionStaticTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoTooMuchMemoryTest
[ RUN      ] AddressSanitizer.LongDoubleNegativeTest
[       OK ] AddressSanitizer.LongDoubleNegativeTest (0 ms)
[----------] 19 tests from AddressSanitizer (27890 ms total)

[----------] Global test environment tear-down
[==========] 22 tests from 2 test suites ran. (27894 ms total)
[  PASSED  ] 22 tests.

  YOU HAVE 1 DISABLED TEST

Step 34 (run instrumented asan tests [aarch64/bluejay-userdebug/TQ3A.230805.001]) failure: run instrumented asan tests [aarch64/bluejay-userdebug/TQ3A.230805.001] (failure)
...
[ RUN      ] AddressSanitizer.HasFeatureAddressSanitizerTest
[       OK ] AddressSanitizer.HasFeatureAddressSanitizerTest (0 ms)
[ RUN      ] AddressSanitizer.CallocReturnsZeroMem
[       OK ] AddressSanitizer.CallocReturnsZeroMem (13 ms)
[ DISABLED ] AddressSanitizer.DISABLED_TSDTest
[ RUN      ] AddressSanitizer.IgnoreTest
[       OK ] AddressSanitizer.IgnoreTest (0 ms)
[ RUN      ] AddressSanitizer.SignalTest
[       OK ] AddressSanitizer.SignalTest (210 ms)
[ RUN      ] AddressSanitizer.ReallocTest
[       OK ] AddressSanitizer.ReallocTest (30 ms)
[ RUN      ] AddressSanitizer.WrongFreeTest
[       OK ] AddressSanitizer.WrongFreeTest (134 ms)
[ RUN      ] AddressSanitizer.LongJmpTest
[       OK ] AddressSanitizer.LongJmpTest (0 ms)
[ RUN      ] AddressSanitizer.ThreadStackReuseTest
[       OK ] AddressSanitizer.ThreadStackReuseTest (11 ms)
[ DISABLED ] AddressSanitizer.DISABLED_MemIntrinsicUnalignedAccessTest
[ DISABLED ] AddressSanitizer.DISABLED_LargeFunctionSymbolizeTest
[ DISABLED ] AddressSanitizer.DISABLED_MallocFreeUnwindAndSymbolizeTest
[ RUN      ] AddressSanitizer.UseThenFreeThenUseTest
[       OK ] AddressSanitizer.UseThenFreeThenUseTest (122 ms)
[ RUN      ] AddressSanitizer.FileNameInGlobalReportTest
[       OK ] AddressSanitizer.FileNameInGlobalReportTest (113 ms)
[ DISABLED ] AddressSanitizer.DISABLED_StressStackReuseAndExceptionsTest
[ RUN      ] AddressSanitizer.MlockTest
[       OK ] AddressSanitizer.MlockTest (0 ms)
[ DISABLED ] AddressSanitizer.DISABLED_DemoThreadedTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoStackTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoThreadStackTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFLowIn
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFLowLeft
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFLowRight
[ DISABLED ] AddressSanitizer.DISABLED_DemoUAFHigh
[ DISABLED ] AddressSanitizer.DISABLED_DemoOOM
[ DISABLED ] AddressSanitizer.DISABLED_DemoDoubleFreeTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoNullDerefTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoFunctionStaticTest
[ DISABLED ] AddressSanitizer.DISABLED_DemoTooMuchMemoryTest
[ RUN      ] AddressSanitizer.LongDoubleNegativeTest
[       OK ] AddressSanitizer.LongDoubleNegativeTest (0 ms)
[----------] 19 tests from AddressSanitizer (27890 ms total)

[----------] Global test environment tear-down
[==========] 22 tests from 2 test suites ran. (27894 ms total)
[  PASSED  ] 22 tests.

  YOU HAVE 1 DISABLED TEST
program finished with exit code 0
elapsedTime=2328.708550

```

</details>

https://github.com/llvm/llvm-project/pull/128122