Reuse StructuralHash and allow it to be used in non-expensive checks builds.
Move PreservedAnalysisChecker further down StandardInstrumentations so other Instrumentations (e.g. printing) have a chance to run before PreservedAnalysisChecker crashes.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D146003
Simplifies the implementation of `TypeSize` while retaining its interface.
There is no need for abstract concepts like `LinearPolyBase`, `UnivariateLinearPolyBase` or `LinearPolySize`.
Differential Revision: https://reviews.llvm.org/D140263