Create the contexts of parameter declaration clauses within the context-builder, not within the type-builder.
Now use-building works correctly within function-definition parameter declaration clauses: It can find types/values defined within the local class now.

Also this makes not only all the highlighting within parameter-declaration clauses work nicely, but it also seems to fix many other highlighting problems that seem to have been side-effects of overlapping smart-ranges.

Yeehaw :-)