tests/lint: test old-style functions in a lint library

To really qualify as old-style, a function must not declare a return
type in its definition.

tests/lint: test writing of a lint library

The code for that is almost the same as in lint1, but only almost.

lint: write the entries for the libraries in alphabetical order

This makes them easier to read by humans.

The checks are still performed in hashcode order since there are no
tests that would cover this change.

tests/lint: normalize whitespace in lint2 tests

Found a typo in read.ln, f124, which had just 'F' instead of the
intended 'F0'. Other than that, only whitespace changes.

lint: allow libraries to use 128-bit integer types