[mlir] Allow trailing digit for alias in AsmPrinter (#127993)

When generating aliases from `OpAsm{Dialect,Type,Attr}Interface`, the
result would be sanitized and if the alias provided by the interface has
a trailing digit, AsmPrinter would attach an underscore to it to
presumably prevent confliction.

#### Motivation

There are two reasons to motivate the change from the old behavior to
the proposed behavior

1. If the type/attribute can generate unique alias from its content,
then the extra trailing underscore added by AsmPrinter will be strange

```mlir
  func.func @add(%ct: !ct_L0_) -> !ct_L0_
    %ct_0 = bgv.add %ct, %ct : (!ct_L0_, !ct_L0_) -> !ct_L0_
    %ct_1 = bgv.add %ct_0, %ct_0 : (!ct_L0_, !ct_L0_) -> !ct_L0_
    %ct_2 = bgv.add %ct_1, %ct_1 : (!ct_L0_, !ct_L0_) -> !ct_L0_
    return %ct_2 : !ct_L0_
  }
```

Which aesthetically would be better if we have `(!ct_L0, !ct_L0) ->
!ct_L0`

2. The Value name behavior is that, for the first instance, use no
suffix `_N`, which can be similarly applied to alias name. See the IR
above where the first one is called `%ct` and others are called `%ct_N`.
See `uniqueValueName` for detail.

#### Conflict detection


```mlir
!test.type<a = 3> // suggest !name0
!test.type<a = 4> // suggest !name0
!test.another<b = 3> // suggest !name0_
!test.another<b = 4> // suggest !name0_
```

The conflict detection is based on `nameCounts` in `initializeAliases`,
where

In the original way, the first two will get sanitized to `!name0_` and
`initializeAlias` can assign unique id `0, 1, 2, 3` to them.

In the current way, the `initializeAlias` uses `usedAliases` to track
which name has been used, and use such information to generate a suffix
id that will make the printed alias name unique.

The result for the above example is `!name0, !name0_1, !name0_,
!name0_2` now.
4 files changed
tree: e4a6389dcb31364b3c18140600ba1f1750bb7c3a
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. SECURITY.md
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