* This allows better identification of a shader from its reflection
bundle. The entry point was already 'optionally' in the debug info
struct which is no longer a great location for it.
* For APIs where the entry point isn't contractual and it might not be
listed, instead we just fall back to 'main'. This means that the UI
or anyone fetching the info can be guaranteed that some sensible entry
point will be listed.
* Also for the debug info, remove the 'entryFile' index and instead just
guarantee that as much as possible the entry point will be in the
first file in the list.
baldurk
bdf2a68c71