[LV] Add debug output to print interleaved groups

[anna]

Summary

Add interleaved groups available after interleave analysis is done.
See updated tests.

[anna]

shall I go ahead and land this? Simple enough change.

[fhahn]

llvm/lib/Analysis/VectorUtils.cpp

31

IMO it would be fine to print this with general debug?

llvm/test/Transforms/LoopVectorize/X86/vector_ptr_load_store.ll

1

unrelated change?

[anna]

llvm/lib/Analysis/VectorUtils.cpp

31

Sure, it would update many tests, but that would be better I suppose to see what happens.

llvm/test/Transforms/LoopVectorize/X86/vector_ptr_load_store.ll

1

With the -debug flag it was printing out the interleaved groups as well, which I felt takes away focus from the main check lines.

[Ayal]

llvm/include/llvm/Analysis/VectorUtils.h

654

Would it be better to have InterleaveGroup::print(raw_ostream &OS) take care of dumping its members, possibly along with their indices, designated InsertPos, and IG's Factor/Reverse/Alignment attributes?
Under #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)