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

[Rahul Joshi via llvm-commits]

jurahul wrote:

Note that this file/API was last updated in any meaningful way in 2009 and has since then not changed. Hence the guess that it is unused at this point.

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