Add HIP language support

[Young-TW]

Description

This pull request adds support for the HIP programming language used in AMD's ROCm ecosystem for GPU programming. HIP is a C++-based parallel computing language, similar in structure to CUDA, and is widely used in projects targeting AMD GPUs.

• I am adding a new language.
  • The extension of the new language is used in hundreds of repositories on GitHub.com.
    • Search results for .hip extension:
      • https://github.com/search?q=NOT+is%3Afork+path%3A*.hip+__global__&type=code
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s): Authored for this PR
    • Sample license(s): Licensed under the MIT license (same as Linguist)
  • I have included a syntax highlighting grammar:
    • Reused existing C++ grammar from https://github.com/textmate/c.tmbundle
  • I have added a color
    • Hex value: #4F3A4F
    • Rationale: A dark reddish color was chosen to reflect AMD's branding, in contrast to NVIDIA's green typically associated with CUDA.
      theme.
  • I have updated the heuristics to distinguish my language from others using the same extension.
    • Not necessary — the .hip extension is unique to HIP.

Thanks for reviewing!

[lildude]

The sample you've provided is very small. I recommend adding a one or two more which are representative of the language as these files are used to train the classifier in the event another language with a matching extension is added in future. Small samples result in poor training data and thus poor analysis.

[Young-TW]

Thanks for the suggestion! I'll add a few more representative HIP samples to improve the training data and update the PR shortly.

[lildude]

Thanks for the new samples however several are too big - if they're suppressed in the diff, they're too big. We also don't accept "Hello world" samples as stated in the CONTRIBUTING.md file.

[Young-TW]

Thanks for the clarification!

I'll replace the current samples with smaller, more representative ones from the same source and remove the HelloWorld sample per the CONTRIBUTING guidelines. Will update the PR shortly.

I picked these from AMD’s official ROCm HIP-Examples repo to ensure they reflect real-world usage, but I understand the importance of size constraints and avoiding trivial examples.

[lildude]

LGTM. Thanks.

Important

The changes in this PR will not appear on GitHub until the next release has been made and deployed. See here for more details.