Updating the open integration jobs to use the new image.

fixed overload resolution being changed

Fixes https://github.com/dotnet/roslyn/issues/14998

Removing unecessary 'label' statements from the netci.groovy

simplify syntax tree task caching

add object dispose check to one missing place.

add fail fast on exceptional situation

Updating `RoslynProjectType=UnitTestNext` to not set `_CopyReferences=false`

Updating the 'locate-vs.ps1' script to return an empty string if there are no Dev15 instances installed on the machine.

Separate out unit test projects

update nuget packages for scripting to support netstandard1.3 instead…

Simplify services for remove-unnecessary-import/using.

are no Dev15 instances installed on the machine.

Don't rely on %RoslynRoot% being set

Use the RC SDK to build if you're on RC

Outline expression bodied members.

Fixes #9238