Detect infinite generic expansion

[hez2010]

Previous discussion: https://github.com/dotnet/corert/issues/363

We need to detect infinite generic expansion and terminate type loading.

Affected test:

JIT\Methodical\inlining\bug505642\test\

.NET Native for UWP apps uses Tarjan's algorithm to find strongly connected components in the graph of constructed types.

The task is to:

• Figure out how to run the algorithm in parallel with code generation (in .NET Native for UWP apps, this is a global pre-pass, but we don't have global pre-passes here)
• Convert static generic lookups to lazy lookups to break the connected component. Lazy lookups are not wired up yet, so maybe that should be the first thing to do.

Here's a couple test cases: recursion.zip. We would be able to solve the ones where the recursion happens over reference types. If the recursion happens over value types, this is not solvable without universal shared code.

[MichalStrehovsky]

This is mostly done but I would like to avoid the spurious NullReferenceExceptions when cutoff happens, and I would like the compiler to print some sort of useful feedback when the cutoff happens so that people can ideally remove the generic cycle from the source.

[MichalStrehovsky]

Fixed in #1681, #1699, #1709, #1710.