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.
- Set the builder's debug scope to the remapped debug scope in the overriden visiters.
- In trampoline blocks where we build predecessor enums, make the trampoline builder inherit the original terminator's remapped debug scope.
Resolves rdar://74087329.
