[release/6.0-preview7] Eliminate backtracking in the interpreter for patterns with .*

[github-actions]

Backport of #51508 to release/6.0-preview7

/cc @pgovind

Customer Impact

1. Optimize regex patterns containing .* in them. In my performance tests (part of the original PR), I get a speed up of 6x

Testing

1. Added ~25 new unit tests with .* and various patterns (strings/numbers/case sensitivity/RightToLeft)
2. We also already have ~130 unit tests with the .* pattern

Risk

1. Minimal. The changes in this PR are pure optimizations and don't change the current behavior. All this PR does is short-circuit a number of inefficient backtracking steps.

[ghost]

Tagging subscribers to this area: @eerhardt, @dotnet/area-system-text-regularexpressions
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Issue Details

---

Backport of #51508 to release/6.0-preview7

/cc @pgovind

Customer Impact

Testing

Risk

Author:	github-actions[bot]
Assignees:	-
Labels:	area-System.Text.RegularExpressions, community-pr
Milestone:	-

[danmoseley]

This is approved to merge. The test failure is unrelated.

[danmoseley]

matches main.

[ghost]

Hello @danmoseley!

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[BrennanConroy]

FYI, this change (in RC1) likely broke some tests in ASP.NET Core dotnet/aspnetcore#34491

Looking into the previous and current behavior, will post in a couple minutes the results.

[BrennanConroy]

Rule: (.*)/(.*).aspx
Input: /pages/homepage.aspx

Expected backreferences:

1. /pages/homepage.aspx
2. /pages
3. homepage

Actual backreferences: None, didn't match

@danmoseley@safern@pgovind I don't think this was intended to be a breaking change

[stephentoub]

I don't think this was intended to be a breaking change

It was not. This should be reverted.

On .NET 5, Console.WriteLine(Regex.IsMatch("/pages/homepage.aspx", "(.*)/(.*).aspx")); prints true.
With this change, Console.WriteLine(Regex.IsMatch("/pages/homepage.aspx", "(.*)/(.*).aspx")); prints false.

[pgovind]

I don't think this was intended to be a breaking change

It was not. I think I see the problem. Let's revert this change for now