When expanding SCEV adds to geps, transfer the nuw flag to the resulting
gep. (Note that this doesn't apply to IV increment GEPs, which go
through a different code path.)

This patch canonicalizes constant expression GEPs to use i8 source
element type, aka ptradd. This is the ConstantFolding equivalent of the
InstCombine canonicalization introduced in #68882.

I believe all our optimizations working on constant expression GEPs
(like GlobalOpt etc) have already been switched to work on offsets, so I
don't expect any significant fallout from this change.

This is part of:
https://discourse.llvm.org/t/rfc-replacing-getelementptr-with-ptradd/68699

IR is now always parsed in opaque pointer mode, unless
-opaque-pointers=0 is explicitly given. There is no automatic
detection of typed pointers anymore.

The -opaque-pointers=0 option is added to any remaining IR tests
that haven't been migrated yet.

Differential Revision: https://reviews.llvm.org/D141912

This fixes the lower and upper bound calculation of a
RuntimeCheckingPtrGroup when it has more than one loop
invariant pointers. Resolves PR50686.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D104148

The exit blocks of the versioned and non-versioned loops are not dedicated and thus the two loops are not in simplify form.
Insert dummy exit blocks after loop versioning with `formDedicatedExits()` to preserve the simplify form for subsequence passes.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D89569

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546