Created Issue: Can't close VS while analyzing ghost [1221]

https://github.com/TryGhost/Ghost

Create project from existing code.
IntelliSense set to Full.

After about 1.5-2.0 hours, it wasn't anywhere near finished analyzing so I decided to close VS. NTVS wasn't ready to give up on analysis, it just kept going and VS was frozen and not closing.


Check the stack from the main thread:

```
WindowsBase.dll!System.Windows.Threading.DispatcherSynchronizationContext.Wait(System.IntPtr[] waitHandles, bool waitAll, int millisecondsTimeout) + 0x22 bytes
mscorlib.dll!System.Threading.SynchronizationContext.InvokeWaitMethodHelper(System.Threading.SynchronizationContext syncContext, System.IntPtr[] waitHandles, bool waitAll, int millisecondsTimeout) + 0x12 bytes
[Native to Managed Transition]
[Managed to Native Transition]
Microsoft.NodejsTools.dll!Microsoft.NodejsTools.Intellisense.AnalysisQueue.Stop() + 0x45 bytes
> Microsoft.NodejsTools.dll!Microsoft.NodejsTools.Intellisense.VsProjectAnalyzer.Dispose() + 0x17f bytes
Microsoft.NodejsTools.dll!Microsoft.NodejsTools.Project.NodejsProjectNode.Dispose(bool disposing) + 0x11c bytes
Microsoft.NodejsTools.dll!Microsoft.VisualStudioTools.Project.HierarchyNode.Close() + 0x61 bytes
Microsoft.NodejsTools.dll!Microsoft.VisualStudioTools.Project.ProjectNode.Close() + 0x7c bytes
Microsoft.NodejsTools.dll!Microsoft.VisualStudioTools.Project.CommonProjectNode.Close() + 0xd1 bytes
Microsoft.NodejsTools.dll!Microsoft.VisualStudioTools.Project.ProjectNode.Microsoft.VisualStudio.Shell.Interop.IVsHierarchy.Close() + 0x1f bytes
[Native to Managed Transition]
[Managed to Native Transition]
Microsoft.VisualStudio.Web.Application.dll!Microsoft.VisualStudio.Web.Application.WAProject.Close() + 0x50 bytes
Microsoft.VisualStudio.Web.Application.dll!Microsoft.VisualStudio.Web.Application.FlavoredProjectBase.Microsoft.VisualStudio.Shell.Interop.IVsHierarchy.Close() + 0x13 bytes
[Native to Managed Transition]
[Managed to Native Transition]
Microsoft.NodejsTools.dll!Microsoft.NodejsTools.NodejsProject.Close() + 0xd0 bytes
Microsoft.VisualStudio.Shell.11.0.dll!Microsoft.VisualStudio.Shell.Flavor.FlavoredProjectBase.Microsoft.VisualStudio.Shell.Interop.IVsHierarchy.Close() + 0x13 bytes
[Native to Managed Transition]
```

The stack from Node.js Analysis Queue:

```
> Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.VariableDef.TypesNoCopy.get() + 0x130 bytes
Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.Values.ObjectValue.Get(Microsoft.NodejsTools.Parsing.Node node, Microsoft.NodejsTools.Analysis.AnalysisUnit unit, string name, bool addRef) + 0x87 bytes
Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.AnalysisSetExtensions.Get(Microsoft.NodejsTools.Analysis.IAnalysisSet self, Microsoft.NodejsTools.Parsing.Node node, Microsoft.NodejsTools.Analysis.AnalysisUnit unit, string name, bool addRef) + 0x69 bytes
Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.Values.ObjectValue.Get(Microsoft.NodejsTools.Parsing.Node node, Microsoft.NodejsTools.Analysis.AnalysisUnit unit, string name, bool addRef) + 0xb6 bytes
Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.AnalysisSetExtensions.Get(Microsoft.NodejsTools.Analysis.IAnalysisSet self, Microsoft.NodejsTools.Parsing.Node node, Microsoft.NodejsTools.Analysis.AnalysisUnit unit, string name, bool addRef) + 0x69 bytes
Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.Values.ObjectValue.Get(Microsoft.NodejsTools.Parsing.Node node, Microsoft.NodejsTools.Analysis.AnalysisUnit unit, string name, bool addRef) + 0xb6 bytes
Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.AnalysisSetExtensions.Get(Microsoft.NodejsTools.Analysis.IAnalysisSet self, Microsoft.NodejsTools.Parsing.Node node, Microsoft.NodejsTools.Analysis.AnalysisUnit unit, string name, bool addRef) + 0x69 bytes
Microsoft.NodejsTools.Analysis.dll!Microsoft.NodejsTools.Analysis.Values.ObjectValue.Get(Microsoft.NodejsTools.Parsing.Node node, Microsoft.NodejsTools.Analysis.AnalysisUnit unit, string name, bool addRef) + 0xb6 bytes
...
```