improve debug messages in delinearization

In this patch:
1. Adapt the output of printDelinearization() to match what the script
   expects to see, "Printing analysis 'Delinearization' for function".
2. Register the "Delinearization" pass in the update script.
3. Automatically remove the existing CHECK statements.
4. Update the tests with a run of:
```
$ ~/llvm-project/llvm/utils/update_analyze_test_checks.py
        --opt=~/llvm-project/build/bin/opt
        ~/llvm-project/llvm/test/Analysis/Delinearization/*.ll
```
5. Drop llvm/test/Analysis/Delinearization/undef.ll because the test
   does not pass the github-actions "undef deprecator."
6. Only run delinearization pretty-print pass on the most internal loop.
7. Only run delinearization pretty-print pass on load and store
   instructions.

The existing functions `getIndexExpressionsFromGEP` and
`tryDelinearizeFixedSizeImpl` provide functionality to delinearize
memory accesses for fixed size array. They use the GEP source element
type in their optimization heuristics. However, driving optimization
heuristics based on GEP type information is not allowed.

This patch introduces new functions `findFixedSizeArrayDimensions` and
`delinearizeFixedSizeArray` to delinearize a fixed size array without
using the type information in GEP. The new function
`findFixedSizeArrayDimensions` infers the size of each dimension of the
array based on the value to be added to the address as induction
variables are incremented. `delinearizeFixedSizeArray` attempts to
restore the subscripts of each dimension based on the estimated array
size.

This is an initial implementation that may not cover all cases, but is
intended to replace the existing function in the future.

Related:
- https://discourse.llvm.org/t/enabling-loop-interchange/82589/4
-
https://github.com/llvm/llvm-project/pull/124911#issuecomment-2962499501

Identified with misc-include-cleaner.

Use const SCEV * explicitly in more places to prepare for
https://github.com/llvm/llvm-project/pull/91961. Split off as suggested.

This pass isn't used/tested anywhere in upstream LLVM, so remove it.

This is a follow-up patch to D122857 where we added delinearization of
fixed-size arrays to loop cache analysis, which resulted in some duplicate
code, i.e., "tryDelinearizeFixedSize()", in LoopCacheCost.cpp and
DependenceAnalysis.cpp. Refactoring is done in this patch.

This patch refactors out the main logic of "tryDelinearizeFixedSize()" as
"tryDelinearizeFixedSizeImpl()" and moves it to Delinearization.cpp, such that
clients can reuse "llvm::tryDelinearizeFixedSizeImpl()" wherever they would
like to delinearize fixed-size arrays. Currently it has two users, i.e.,
DependenceAnalysis.cpp and LoopCacheCost.cpp.

Reviewed By: Meinersbur, #loopoptwg

Differential Revision: https://reviews.llvm.org/D124745

Number of lines output by preprocessor:
before: 1065940348
after:  1065307662

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D120659