The SIL type lowering logic for AutoDiff gets the substituted generic signature
mixed up with the invocation generic signature, so it tries to ask questions
about DependentMemberTypes in a signature with no requirements. This triggers
assertions when the requirement machine is enabled.
Disable the requirement machine until this is fixed.
`valueWithDerivative(of:)` and `valueWithGradient(of:)` are the curried version of `valueWithDerivative(at:in:)` and `valueWithGradient(at:in:)`, respectively. They are not included the proposal and are not being used by any client that I know of. This patch removes them.