Create new integration test project. For tests assemble il and then use bespoke code to do most of what the MethodCompiler does before running ssa build. Then run the SsaBuilder directly and assert on results e.g. ssa numbers in local variable table
Add some asserts/checks into the ILCompiler itself to check things, see fgDebugCheckSsa in Ryujit for inspiration
There is at most one ssa definition for a given ssa number, and that the definition is in the expected block
Started implementing SSA but lots left to do: