Accoring to the discussion in https://github.com/llvm/llvm-project/pull/140529, we need to SSCL can be created from multiple ignore list files, so we can repeat-fsanitize-ignorelist=. The change is necessary to achieve the feature described in https://github.com/llvm/llvm-project/issues/139128.

Issue #139128 needs to find the last one in the file.

Pull Request: https://github.com/llvm/llvm-project/pull/141697

As discussed in https://github.com/llvm/llvm-project/pull/139772 and
https://github.com/llvm/llvm-project/pull/140529, Matcher::Globs can
keep the order when parsing the case list.

Reviewers: vitalybuka

Reviewed By: vitalybuka

Pull Request: https://github.com/llvm/llvm-project/pull/140316

As discussed in https://github.com/llvm/llvm-project/pull/139772, SpecialCaseList::Sections can keep the order of Sections when parsing the case list.

Reviewers: thurstond, vitalybuka

Reviewed By: vitalybuka

Pull Request: https://github.com/llvm/llvm-project/pull/140127

https://reviews.llvm.org/D154014 addes glob support and enables it when
`#!special-case-list-v2` is the first line. This patch makes the glob
support the default (faster than regex after
https://reviews.llvm.org/D156046) and switches to the deprecated regex
support if `#!special-case-list-v1` is the first line.

I have surveyed many ignore lists. All ignore lists I find only use
basic `*` `.` and don't use regex metacharacters such as `(` and `)`.
(As neither `src:` nor `fun:` benefits from using regex.)
They are unaffected by the transition (with a caution that regex
`src:x/a.pb.*` matches `x/axpbx` but glob `src:x/a.pb.*` doesn't).

There is no deprecating warning. If a user finds
`#!special-case-list-v1`, they shall read that the old syntax is
deprecated.

Link:
https://discourse.llvm.org/t/use-glob-instead-of-regex-for-specialcaselists/71666

startswith/endswith wrap starts_with/ends_with and will eventually go away (to more closely match string_view)

Add an option in `SpecialCaseList` to use Globs instead of Regex to match patterns. `GlobPattern` was extended in https://reviews.llvm.org/D153587 to support brace expansions which allows us to use patterns like `*/src/foo.{c,cpp}`. It turns out that most patterns only take advantage of `*` so using Regex was overkill and required lots of escaping in practice. This often led to bugs due to forgetting to escape special characters.

Since this would be a breaking change, we temporarily support Regex by default and use Globs when `#!special-case-list-v2` is the first line in the file. Users should switch to the glob format described in https://llvm.org/doxygen/classllvm_1_1GlobPattern.html. For example, `(abc|def)` should become `{abc,def}`.

See discussion in https://reviews.llvm.org/D152762 and https://discourse.llvm.org/t/use-glob-instead-of-regex-for-specialcaselists/71666.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D154014

`TrigramIndex` was added back in https://reviews.llvm.org/D27188 as an optimization to make `SpecialCaseList::match()` faster. I've found that `TrigramIndex` actually makes the function slower and it has no functional use, so we can remove it.

I grabbed the list of queries passed to `SpecialCaseList::match()` on a random very large file (`AArch64ISelLowering.cpp`) and measured the runtime to call `match()` on all of them with [this line](https://github.com/llvm/llvm-project/blob/8e1f820bb4eadf5c0704818f6063e0db1006e32d/llvm/lib/Support/SpecialCaseList.cpp#L64) disabled and then enabled.

```
$ hyperfine --warmup 3 'GTEST_FILTER="SpecialCaseListTest.Large" USE_TRIGRAMS=1 build/unittests/Support/SupportTests' 'GTEST_FILTER="SpecialCaseListTest.Large" USE_TRIGRAMS=0 build/unittests/Support/SupportTests'
Benchmark 1: GTEST_FILTER="SpecialCaseListTest.Large" USE_TRIGRAMS=1 build/unittests/Support/SupportTests
  Time (mean ± σ):     575.9 ms ±  20.3 ms    [User: 573.1 ms, System: 2.7 ms]
  Range (min … max):   555.5 ms … 620.0 ms    10 runs

Benchmark 2: GTEST_FILTER="SpecialCaseListTest.Large" USE_TRIGRAMS=0 build/unittests/Support/SupportTests
  Time (mean ± σ):     283.4 ms ±   6.7 ms    [User: 280.3 ms, System: 3.0 ms]
  Range (min … max):   277.0 ms … 294.9 ms    10 runs

Summary
  'GTEST_FILTER="SpecialCaseListTest.Large" USE_TRIGRAMS=0 build/unittests/Support/SupportTests' ran
    2.03 ± 0.09 times faster than 'GTEST_FILTER="SpecialCaseListTest.Large" USE_TRIGRAMS=1 build/unittests/Support/SupportTests'
```

Using `perf` I found that most of the runtime in `TrigramIndex::isDefinitelyOut()` comes from a division operation that seems to come from `std::unordered_map`: https://github.com/llvm/llvm-project/blob/8e1f820bb4eadf5c0704818f6063e0db1006e32d/llvm/include/llvm/Support/TrigramIndex.h#L62

Removing `TrigramIndex` will make it easier to potentially switch to using `GlobPattern` instead of a full regex for `SpecialCaseList`. See discussion in https://reviews.llvm.org/D152762 for details.

Reviewed By: MaskRay, #sanitizers, vitalybuka

Differential Revision: https://reviews.llvm.org/D153171