Update v8-feature-tracker

Author: RexJaeschke

admin/v8-feature-tracker.md

@@ -10,12 +10,12 @@ alternative interpolated verbatim strings ([MS Proposal](https://github.com/dotn
 async streams ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/async-streams.md)) | [606](https://github.com/dotnet/csharpstandard/pull/606) | Completed | small | Done | PR [672](https://github.com/dotnet/csharpstandard/pull/672) will be layered on top of this
 using declarations and async using ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/using.md)), ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/async-using.md)) | [672](https://github.com/dotnet/csharpstandard/pull/672) | Completed | small |  Done | This PR will be layered on top of PR [606](https://github.com/dotnet/csharpstandard/pull/606); reconcile any overlap
 override with constraints ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/constraints-in-overrides.md)) | [671](https://github.com/dotnet/csharpstandard/pull/671) | Completed | small |  Done |
-unmanaged constructed types ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/constructed-unmanaged.md)) | [604](https://github.com/dotnet/csharpstandard/pull/604) | Completed | small | N/A |
+unmanaged constructed types ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/constructed-unmanaged.md)) | [604](https://github.com/dotnet/csharpstandard/pull/604) | Merged | small | N/A |
 default interface methods ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/default-interface-methods.md)) | [681](https://github.com/dotnet/csharpstandard/pull/681) | Completed | medium |  Done |
-permit `stackalloc` in nested contexts ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/nested-stackalloc.md)) | [1056](https://github.com/dotnet/csharpstandard/pull/1056) | Completed | small | N/A | 
+permit `stackalloc` in nested contexts ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/nested-stackalloc.md)) | [1056](https://github.com/dotnet/csharpstandard/pull/1056), [1211](https://github.com/dotnet/csharpstandard/pull/1211) | Merged | small | N/A | 
 `notnull` constraint ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/notnull-constraint.md)) | [830](https://github.com/dotnet/csharpstandard/pull/830) | Completed | small |  Done | 
 null coalescing assignment ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/null-coalescing-assignment.md)) | [609](https://github.com/dotnet/csharpstandard/pull/609) | HELP NEEDED | small |  N/A | See Issue [#737](https://github.com/dotnet/csharpstandard/issues/737)
-nullable reference types ([MS Proposal (from V9)](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-9.0/nullable-reference-types-specification.md) which supercedes ([MS Proposal (from V8)](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/nullable-reference-types.md)) |[700](https://github.com/dotnet/csharpstandard/pull/700), [1195](https://github.com/dotnet/csharpstandard/pull/1195) | Completed | large  | Done | related to V8 "notnull" feature 
+nullable reference types ([MS Proposal (from V9)](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-9.0/nullable-reference-types-specification.md) which supercedes ([MS Proposal (from V8)](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/nullable-reference-types.md)) |[700](https://github.com/dotnet/csharpstandard/pull/700), [1178](https://github.com/dotnet/csharpstandard/pull/1178), [1191](https://github.com/dotnet/csharpstandard/pull/1191), [1192](https://github.com/dotnet/csharpstandard/pull/1192), [1195](https://github.com/dotnet/csharpstandard/pull/1195) | Merged | large  | Done | related to V8 "notnull" feature 
 Obsolete on property accessor ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/obsolete-accessor.md)) | **no change needed** | Postponed | | N/A | See Issue [#375](https://github.com/dotnet/csharpstandard/issues/375)
 New kinds of pattern matching ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/patterns.md)) | [873](https://github.com/dotnet/csharpstandard/pull/873) | Completed | medium | Done | precedence table assumes "ranges and indices" has been merged
 ranges and indices ([MS Proposal](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-8.0/ranges.md)) | [605](https://github.com/dotnet/csharpstandard/pull/605) | Completed | medium | Done |