[llvm] [NFC][LLVM] Remove unused `TargetIntrinsicInfo` class (PR #126003)

[Rahul Joshi via llvm-commits]

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@@ -61,6 +61,8 @@ Changes to the LLVM IR
 Changes to LLVM infrastructure
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+* The `TargetIntrinsicInfo` support has been removed.
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jurahul wrote:

The commit that added this has the description: "add support for target intrinsics being defined in the
target directories themselves". I can word this as: 

Removed support for target intrinsics being defined in the target directories themselves (i.e., the `TargetIntrinsicInfo` class).

https://github.com/llvm/llvm-project/pull/126003