This reverts commit adaff46d087799072438dd744b038e6fd50a2d78.

Drop the -O3 checks from default-attributes.hip. I don't know why they
are different on some bots but reverting this is far too disruptive.

This reverts commits 677cc15e0ff2e0e6aa30538eb187990a6a8f53c0 and
78bc1b64a6dc3fb6191355a5e1b502be8b3668e7.

The test CodeGenHIP/default-attributes.hip is failing on multiple bots
even after the attempted fix including the following:
- https://lab.llvm.org/buildbot/#/builders/3/builds/1473
- https://lab.llvm.org/buildbot/#/builders/65/builds/1380
- https://lab.llvm.org/buildbot/#/builders/161/builds/595
- https://lab.llvm.org/buildbot/#/builders/154/builds/1372
- https://lab.llvm.org/buildbot/#/builders/133/builds/1547
- https://lab.llvm.org/buildbot/#/builders/81/builds/755
- https://lab.llvm.org/buildbot/#/builders/40/builds/570
- https://lab.llvm.org/buildbot/#/builders/13/builds/748
- https://lab.llvm.org/buildbot/#/builders/12/builds/1845
- https://lab.llvm.org/buildbot/#/builders/11/builds/1695
- https://lab.llvm.org/buildbot/#/builders/190/builds/1829
- https://lab.llvm.org/buildbot/#/builders/193/builds/962
- https://lab.llvm.org/buildbot/#/builders/23/builds/991
- https://lab.llvm.org/buildbot/#/builders/144/builds/2256
- https://lab.llvm.org/buildbot/#/builders/46/builds/1614

These bots have been broken for a day, so reverting to get everything
back to green.

Removing it from the codegen pipeline induces a lot of test churn
because llc is no longer optimizing out implicit arguments to kernels.

Mostly mechanical, but there are some creative test updates. I preferred
to take the changes as-is in tests where the ABI isn't relevant. In
cases where it's more relevant, or the optimize out logic was too
ingrained in the test, I pre-run the optimization. Some cases manually
add attributes to disable inputs.

Previously reverted in 8b446ea2ba39e406bcf940ea35d6efb4bb9afe95

Reapplying because this commit is NOT DEPENDENT on the reverted commit
fc21f2d7bae2e0be630470cc7ca9323ed5859892, which broke the ASAN buildbot.
See https://reviews.llvm.org/rGfc21f2d7bae2e0be630470cc7ca9323ed5859892 for
more information.

The arguments to a PHI may represent a recurrence by eventually using the output
of the PHI itself. This is now handled by checking for cycles in the control
flow. If a PHI is not in a recurrence, it is now able to report multiple offsets
instead of conservatively reporting unknown.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D138991

This reverts commit 88db516af69619d4326edea37e52fc7321c33bb5.

Reason: This change is dependent on a commit that needs to be rolled
back because it broke the ASan buildbot. See
https://reviews.llvm.org/rGfc21f2d7bae2e0be630470cc7ca9323ed5859892 for
more information.

This reverts commit 12696d302d146ffe616eecab3feceba9d29be2db.

Reason: This change is dependent on a commit that needs to be rolled
back because it broke the ASan buildbot. See
https://reviews.llvm.org/rGfc21f2d7bae2e0be630470cc7ca9323ed5859892 for
more information.

This reverts commit 179ed8871101cd197e0a719a3629cd5077b1a999.

Reason: This change is dependent on a commit that needs to be rolled
back because it broke the ASan buildbot. See
https://reviews.llvm.org/rGfc21f2d7bae2e0be630470cc7ca9323ed5859892 for
more information.

Previously reverted in 12696d302d146ffe616eecab3feceba9d29be2db

The arguments to a PHI may represent a recurrence by eventually using the output
of the PHI itself. This is now handled by checking for cycles in the control
flow. If a PHI is not in a recurrence, it is now able to report multiple offsets
instead of conservatively reporting unknown.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D138991

This reverts commit 88db516af69619d4326edea37e52fc7321c33bb5.