[PassBuilder] VectorizerEnd Extension Points (#123494)
Added an extension point after vectorizer passes in the PassBuilder.
Additionally, added extension points before and after vectorizer passes
in `buildLTODefaultPipeline`. Credit goes to @mshockwave for guiding me
through my first LLVM contribution (and my first open source
contribution in general!) :)
- Implemented `registerVectorizerEndEPCallback`
- Implemented `invokeVectorizerEndEPCallbacks`
- Added `VectorizerEndEPCallbacks` SmallVector
- Added a command line option `passes-ep-vectorizer-end` to
`NewPMDriver.cpp`
- `buildModuleOptimizationPipeline` now calls
`invokeVectorizerEndEPCallbacks`
- `buildO0DefaultPipeline` now calls `invokeVectorizerEndEPCallbacks`
- `buildLTODefaultPipeline` now calls BOTH
`invokeVectorizerStartEPCallbacks` and `invokeVectorizerEndEPCallbacks`
- Added LIT tests to `new-pm-defaults.ll`, `new-pm-lto-defaults.ll`,
`new-pm-O0-ep-callbacks.ll`, and `pass-pipeline-parsing.ll`
- Renamed `CHECK-EP-Peephole` to `CHECK-EP-PEEPHOLE` in
`new-pm-lto-defaults.ll` for consistency.
This code is intended for developers that wish to implement and run
custom passes after the vectorizer passes in the PassBuilder pipeline.
For example, in #91796, a pass was created that changed the induction
variables of vectorized code. This is right after the vectorization
passes.
