Keep attribute on the same line as a member if they started on a single line

Fixes #11572 

Make tests strongly typed.

* Tests: fix minasync Task<T> to derive from Task

* Tests: provide MinAsyncCorlibRef

This combines the async features of minasync with mincorlib to produce
a minimum unversioned corlib with async stubs.

* Compilation: use System.Object from target corlib

When creating a script compilation without an explicit return type,
System.Object was being resolved via reflection from the host.

This resulted in an implicit dependency of a script compilation on the
host corlib, even if a different corlib was specified as a reference
for the compilation (e.g. Xamarin.iOS).

Fix this by using System.Object as defined in the corlib resovled
for the compilation.

Fix merge issues that made filtering completion to nothing crash VS

Remove SolutionExplorer ProjectItem base classes added in 56136680

Fixes #556 - Add Fields/Constants to VB Nav Bar

Fix incorrect glyph for locals and parameters.

* Add projects for the runner and utilities

* added benview uploader

* added trace-file backup

* remove old scripts and tools

* Misc fixes

* Added a test-this-please jenkins job

Instead using a facade/mixin approach to more cleanly pull this off.

* Update VirtualTreePoint.cs

Correct the braces so that they are escaped.

* Update VirtualTreePoint.cs

Convert the `String.Format` to an Interpolation String.

* Update VirtualTreePoint.cs

Correct the variable.

removed culture dependency from ConversionsTests

Block any commits that derive from a bad merge we removed via force push

- It should no longer block future -> master merges, since we've done
  that now.
- It should block any new pull requests that contain the previous
  bad merge.

Fixes #11559

fix issue with telemetry.

Replace property with method

it looks like diagnostic telemetry got broken when we introduced a new flag for diagnostic engines in update 1.

also recent engine v2 changes didn't report all telemetry data

Merge master into future

Make compiler familiar with TH2 format of DeprecatedAttribute.