Update Language Feature Status.md

Fixes #40768.

* Update required dotnet to 3.1.100

* Update required VS to 16.4

Minor grammar fixes in markdown file

use MIT license

LOC CHECKIN | dotnet/roslyn master | 20200116

Override definition string content to exclude hashcode for screen rea…

Straightforward cleanup in our simplification code.

Moves an ArrayBuilder for DeclaredEnvironments to a single environment.
This means that a scope only declares a single closure environment for its
captured variables.

I left space for us to declare multiple closure environments
in a single scope, but that seems like over-engineering at the
moment and it makes a lot of code more complicated. We can
always add it back if it seems like it would be worth it

Filter identifier name simplification according to aliases and predefined types

- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20071.3

Fix regression in code fix service

My recent change #40814 causes a crash in code fix service when there are duplicate diagnostics with same location and ID. This change adds a unit test to verify the regression and fixes the crash by using a SortedSet with a comparer.

Fixes #41116

Merge pull request #41007 from siegfriedpammer/dev/siegfriedpammer/decompiledsources-asm-resolver-improvements

Improving F12 Decompilation Quality By Passing Fuzzy-Matched References

Avoid trying to simplify descendant identifier names

Improved per-edit performance in AnalyzerRunner

Previously we reported diagnostics caused by the debuggee not allowing edits in the corresponding module in EnC diagnostic analyzer.
A module does not support edits if any of its instances does not support the edits. There are scenarios in which module instances may be loaded while in break mode.
E.g. if the user attaches to a secondary process while debugging a primary process, the secondary process might have a module instance loaded of the same module loaded to the primary process.
To handle these cases we hooked up debugger module load/unload events and invalidated the reported diagnostics.

This approach has a few problems:
1) EnC analyzer is now non-deterministic, as it can give different answers for the same inputs depending on the state of the debuggee
2) Turns out that the debugger does not deliver module load/unload events in all cases (e.g. when the secondary process is killed).
3) It's a bit complicated and would get even more complicated once we moved EnC to OOP/Cloud

Instead, we don't report these errors until the user triggers the "continue" action. At this point the VS and all processes being debugged are blocked until the changes analyzed and applied.
Since this situation is not very common the slight regression in interactivity is acceptable.

Use simple IsKind pattern.

Remove unnecessary check in SimplifyTypeNames.

- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20068.1