Avoid compiler hang from invalid text in AdditionalFiles

[bluetarpmedia]

Added a timeout to NegatableTypeOrMemberReferenceRegex and MemberReferenceRegex to prevent a CPU hang when given input that causes (what I believe to be) very expensive regex backtracking.

Incidentally, some invalid input causes a hang but other invalid input just causes a no-match (as expected).

These cause a hang (or timeout when the Regex is given one):

![Microsoft.VisualStudio.Shell.Interop.SVsAppContainerProjectDeploy].   <-- original report

[Microsoft.VisualStud]FooBar
[Microsoft.VisualStudio]FooBar
[aaaaaaaaa.bbbbbbbbbb]FooBar                                            <-- 9 'a' then 10 'b'

But the following do not hang and instead return a Regex with no match (as expected).

[Microsoft.VisualStu]FooBar
[aaaaaaaaa.bbbbbbbbb]FooBar                                             <-- 9 'a' then 9 'b'

Maybe there's something internal to Regex which changes its implementation depending on the length of the input string?

Closes #485

[AArnott]

Thank you for this. Just a couple touch-ups, please.

[AArnott]

@bluetarpmedia tip: Please use descriptive PR titles.

Not great:

Great:

You already use the magic Closes #485 string in the PR description (which is great in other ways as well), so thank you for that.

[bluetarpmedia]

tip: Please use descriptive PR titles.

Will do, thanks!

[AArnott]

Thanks!

[bluetarpmedia]

Looks like the Linux job failed when restoring packages:

Restoring NuGet packages
  Determining projects to restore...
  Restored /home/vsts/work/1/s/src/Microsoft.VisualStudio.Threading/Microsoft.VisualStudio.Threading.csproj (in 6.69 sec).
  Restored /home/vsts/work/1/s/src/Microsoft.VisualStudio.Threading.Analyzers/Microsoft.VisualStudio.Threading.Analyzers.csproj (in 8.43 sec).
  Restored /home/vsts/work/1/s/src/Microsoft.VisualStudio.Threading.Analyzers.VisualBasic/Microsoft.VisualStudio.Threading.Analyzers.VisualBasic.csproj (in 942 ms).
  Restored /home/vsts/work/1/s/src/Microsoft.VisualStudio.Threading.Analyzers.CSharp/Microsoft.VisualStudio.Threading.Analyzers.CSharp.csproj (in 180 ms).
  Restored /home/vsts/work/1/s/src/Microsoft.VisualStudio.Threading.Analyzers.CodeFixes/Microsoft.VisualStudio.Threading.Analyzers.CodeFixes.csproj (in 793 ms).
  Restored /home/vsts/work/1/s/test/Microsoft.VisualStudio.Threading.Tests.Win7RegistryWatcher/Microsoft.VisualStudio.Threading.Tests.Win7RegistryWatcher.csproj (in 16 ms).
  Restored /home/vsts/work/1/s/test/Microsoft.VisualStudio.Threading.Tests/Microsoft.VisualStudio.Threading.Tests.csproj (in 4.55 sec).
  Restored /home/vsts/work/1/s/test/IsolatedTestHost/IsolatedTestHost.csproj (in 6 ms).
  Failed to download package 'Microsoft.VisualStudio.Imaging.Interop.14.0.DesignTime.16.11.31527.49' from 'https://pkgs.dev.azure.com/azure-public/3ccf6661-f8ce-4e8a-bb2e-eff943ddd3c7/_packaging/2a239fd0-3e21-40b0-b9d6-bc122fec7eb2/nuget/v3/flat2/microsoft.visualstudio.imaging.interop.14.0.designtime/16.11.31527.49/microsoft.visualstudio.imaging.interop.14.0.designtime.16.11.31527.49.nupkg'.
  Response status code does not indicate success: 503 (Service Unavailable).
  Failed to download package 'Microsoft.VisualStudio.Imaging.Interop.14.0.DesignTime.16.11.31527.49' from 'https://pkgs.dev.azure.com/azure-public/3ccf6661-f8ce-4e8a-bb2e-eff943ddd3c7/_packaging/2a239fd0-3e21-40b0-b9d6-bc122fec7eb2/nuget/v3/flat2/microsoft.visualstudio.imaging.interop.14.0.designtime/16.11.31527.49/microsoft.visualstudio.imaging.interop.14.0.designtime.16.11.31527.49.nupkg'.
  Response status code does not indicate success: 503 (Service Unavailable).
/opt/hostedtoolcache/dotnet/sdk/5.0.400/NuGet.targets(131,5): error : Failed to download package 'Microsoft.VisualStudio.Imaging.Interop.14.0.DesignTime.16.11.31527.49' from 'https://pkgs.dev.azure.com/azure-public/3ccf6661-f8ce-4e8a-bb2e-eff943ddd3c7/_packaging/2a239fd0-3e21-40b0-b9d6-bc122fec7eb2/nuget/v3/flat2/microsoft.visualstudio.imaging.interop.14.0.designtime/16.11.31527.49/microsoft.visualstudio.imaging.interop.14.0.designtime.16.11.31527.49.nupkg'. [/home/vsts/work/1/s/Microsoft.VisualStudio.Threading.sln]
/opt/hostedtoolcache/dotnet/sdk/5.0.400/NuGet.targets(131,5): error : Response status code does not indicate success: 503 (Service Unavailable). [/home/vsts/work/1/s/Microsoft.VisualStudio.Threading.sln]
/opt/hostedtoolcache/dotnet/sdk/5.0.400/NuGet.targets(131,5): error : The feed 'vssdk-public [https://pkgs.dev.azure.com/azure-public/vside/_packaging/vssdk/nuget/v3/index.json]' lists package 'Microsoft.VisualStudio.Imaging.Interop.14.0.DesignTime.16.11.31527.49' but multiple attempts to download the nupkg have failed. The feed is either invalid or required packages were removed while the current operation was in progress. Verify the package exists on the feed and try again. [/home/vsts/work/1/s/Microsoft.VisualStudio.Threading.sln]
/opt/hostedtoolcache/dotnet/sdk/5.0.400/NuGet.targets(131,5): error :   Unable to find package 'Microsoft.VisualStudio.Imaging.Interop.14.0.DesignTime.16.11.31527.49'. [/home/vsts/work/1/s/Microsoft.VisualStudio.Threading.sln]
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                Write-Error: /home/vsts/work/_temp/dd9bf25a-9219-4cad-be91-161af7b85855.ps1:3
Line |
   3 |  .\init.ps1 -AccessToken $AccessToken  -UpgradePrerequisites
     |  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     | Failure while restoring packages.