[clang] [Mips] Correctly define IntPtrType (PR #145158)

[via cfe-commits]

llvmbot wrote:

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Failed to cherry-pick: f7e8c0fcc45e727ce69a453f53ad3f40d6f5fd95

https://github.com/llvm/llvm-project/actions/runs/16422510576

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/145158