[SPIR-V] Ensure that internal intrinsic functions are inserted at the correct positions (#93552)

The goal of the PR is to ensure that newly inserted internal intrinsic
functions are inserted at the correct positions, and don't break rules
of instruction domination and PHI nodes grouping at top of basic block.
This is a continuation of
https://github.com/llvm/llvm-project/pull/92316 and
https://github.com/llvm/llvm-project/pull/92536