Revert "[IR] Use persistent metadata IDs for printing" (#220334)

This reverts commit 85e903099313aa5ea98d175698aaa40e27a0d743.

The change breaks MSVC builds because an inline SmallPtrSet operation
requires a complete DILocation type. It also causes expensive-check
builds to report that the DXIL pretty-printer modifies its input
without reporting it.

Revert while fixes and test coverage are prepared.

Buildbot failure:
https://lab.llvm.org/buildbot/#/builders/2/builds/60795
Buildbot failure:
https://lab.llvm.org/buildbot/#/builders/187/builds/23268

GitOrigin-RevId: 87d11355951b2cdd87ef3fe1cbfe412b0ad07aa3