Materializing each instance repeated the same FILE_SCHEMA warning.
Keep a thread-safe claim flag on the lazy file reader so concurrent
loads and multiple DATA sections report the ambiguity once per input
file.
Add a lazy Part 21 reader and instance manager that index records
and resolve SDAI instances on demand. Include diagnostics, cache
management, reference indexes, and baseline coverage for lazy reads.
We want to be consistent with the previous layout, to avoid needlessly
breaking existing codes. The header update means client codes are not
required to include all of the stepcode library includes explicitly -
i.e., stepcode itself does not force this requirement with its own
internal includes. However, if client codes do not want to add the
library prefixes to their own includes as we have for stepcode, they
should still be able to add the various includes and work as before.
Adjust the include directory names accordingly.
Clifford Yapp