Optimizer should classify assignments to PseudoVariables as indirect assignments

Remove blocking-wait from completoin when caret is moved.

Address issues with SemanticModel behavior around TupleElementSyntax.

Fixes #14881.
Fixes #15476.

Disabling the integration jobs from running automatically during PRs.

Preserve comments when converting to a VB object literal.

Extension method reducer needs to parenthesize argument to prevent precedence change.

Reduce array allocations while finding types.

Cleanup in FindReferences engine.

Remove dependency between DocComment insertion and Completion.

avoid double-pop in an ignored conversion expression

Update some README files

fixed 2 known OOP issues

Doc comments should be ordered after completion so they don't have to do a blocking wait to see if completion is active.

1. For areas where we don't actually use parallalism, remove use of concurrent collections.
We can switch back to concurrent collections if we ever need them.

2. Use using aliases to make types clearer.

3. Simplify how progress was tracked in FAR.

Merge dev15-rc2 into master

Add StorageLocations for Outlining and Structure-Guide options.

Add a small amount of support for Expression-Bodied properties in CodeModel.

Merge dev15-rc2 into master

make document and syntax changed as high priority changes.