Fix inverted condition in LegacyCompletionCondition

Merge dev16.0 to dev16.1-preview1

Run CI on dev16.1-preview1 branches

Updated wait operations to fix unreliable .editorconfig integration tests

 Disable EnableNgenOptimizationLogDetails

Change supports feature service to use text buffers rather than document.

[master] Update dependencies from dotnet/arcade

- Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19171.3

Fixing completion test harness

Adds the ability to split a namespace declaration at a single type within the same file. This work will be used for move type to namespace as a step for splitting the namespace before moving to a new namespace declaration. May be available as a single refactor as well, but currently is not provided as such.

Fixes #30987

Update async completion and quick info to share BuildClassifiedTextElements

Update Microsoft.VisualStudio.Threading

* Don't warn about #nullable in disabled code:
 - Check if in an active code region before warning about #nullable  or #pragma directives in lower lang versions
 - Add tests

Captures Invalid Dimensions from an array variable declaration and adds it to IVariableOperation

Add max path check at beginning of build

[master] Update dependencies from dotnet/arcade

- Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19171.1