Revert "[IRBuilder] Virtualize IRBuilder"

This reverts commit 0765d3824d069f37596bc5a890399099b776c2a0.
This reverts commit 1b04866a3db9f816a559860f941da067fe1eccf1.

Relevant looking crashes observed on:
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win

GitOrigin-RevId: af480e8c63b27ad247b8430cf124da8bcdf752f8
1 file changed