Fix #1049 by adding a workaround (until Roslyn issue is fixed)

[TymurGubayev]

#1049

Problem

In some circumstances, VisualBasicDataFlowAnalysis.get_ReadInside throws the first time it's called, but works the 2nd time around.

Solution

• replace methodFlow.ReadInside with methodFlow.ReadInsideSafe() a new extension method that just tries to read the property a 2nd time in case of any exception.
• Which part of this PR is most in need of attention/improvement? The test doesn't work atm because of another problem.
• At least one test covering the code changed

[TymurGubayev]

There is a problem with the tests I don't know the proper solution for:

• Roslyn 4.2.0 used by the tests has the System.InvalidOperationException: Unexpected value 'PropertyAccess' of type 'Microsoft.CodeAnalysis.VisualBasic.BoundKind' dotnet/roslyn#68194 in it
• To make the test work, we need a version where that bug is fixed (>= 4.7.0)
• Upgradig Roslyng/MsBuild (first commit in the PR) leads to Cannot convert SimpleImportsClauseSyntax, System.InvalidOperationException: Service of type 'Microsoft.CodeAnalysis.Classification.IEmbeddedLanguageClassificationService' is required to accomplish the task but is not available from the workspace.

[GrahamTheCoder]

Interesting there was a patch for something like that which should be in 4.8, but the issue was never closed: dotnet/roslyn#63921

[GrahamTheCoder]

Many thanks for the fix and attempt to add a test. I think we're penned in by upstream bugs, so in this instance I've cherry picked just your implementation onto master since it seems hard to believe it'll make anything worse, and isn't exactly a huge maintenance burden. I'll close this PR as complete