[llvm] [RemoveDIs][NFC] Remove Instruction constructors that insert prior to Instructions (PR #85980)

[Stephen Tozer via llvm-commits]

SLTozer wrote:

This patch on hold for now, as it seems likely that for the next release we'll be deprecating these functions instead; see discussion [here](https://discourse.llvm.org/t/psa-instruction-constructors-changing-to-iterator-only-insertion/77845).

https://github.com/llvm/llvm-project/pull/85980