Fix parsing routines lost in merges

[cartermp]

There was a sequence of events that damned the repo for a day:

1. I submitted Address several (most?) cases of correctly triggering F# function application signature help in some nested contexts #10961 a while back, with added tests (that passed)
2. @dsyme submitted FCS namespace revamp #10971. This was ultimately merged Wednesday night / Thursday morning (depending on your time zone
3. Merges, branches, possible conflicts, etc. were resolved.
4. Address several (most?) cases of correctly triggering F# function application signature help in some nested contexts #10961 was merged this morning (tests passed, after all!)
5. Merges, branches, possible conflicts, etc. were resolved.
6. main was busted, since tests added in Address several (most?) cases of correctly triggering F# function application signature help in some nested contexts #10961 did not have the accompanying implementation that makes them pass in main!

This simply adds back the correct changes from #10961 so that tests pass again.

[KevinRansom]

Thank you Phillip