Fixes an occasional failure in the ErrorList test.

Fix null check combined with nullable bool test

Pattern-based 'await foreach' should find parameterless 'GetAsyncEnumerator' and 'MoveNextAsync' (#32184)

Fix IDE0055 formatting errors

* Run CI builds for 16.0 preview2 vs-deps PRs

* Trigger branch builds on commit for preview branches

Fixup the triggers

Fixup our triggers for branches.

Publish VSIX installer with build

Change no conversion to idisposable message

Fix parsing regression on switch case expression that is parenthesized unary expression

- Restore previous message to remove any mention of 'public void-returning Dispose method'
- Update test comments to match

Merge Features/enhanced-using to master

Fix async test

Remove prototype comments

- Stop classifying EndKeyword in EndUsingStatement
- Begin classifying ToKeyword in ForStatement
- Begin classifying IfKeyword in TernaryConditionalExpression

Fixes #32161

Merge master to enahanced using

Merge master to enhanced using

Handle GetIntellisenseProjectName returning empty