patch 8.2.4701: Kuka Robot Language files not recognized

Problem:    Kuka Robot Language files not recognized.
Solution:   Recognize *.src and *.dat files. (Patrick Meiser-Knosowski,
            closes vim#10096)

patch 8.2.4700: buffer remains active if WinClosed event throws an ex…

…ception

Problem:    Buffer remains active if a WinClosed event throws an exception.
Solution:   Ignore aborting() when closing the buffer. (closes vim#10097)

patch 8.2.4699: hard to reproduce hang when reading from a channel

Problem:    Hard to reproduce hang when reading from a channel.
Solution:   Check for readahead before starting to wait. (closes vim#10093,
            closes vim#7781, closes vim#6364)

patch 8.2.4698: Vim9: script variable has no flag that it was set

Problem:    Vim9: script variable has no flag that it was set.
Solution:   Add a flag that it was set, to avoid giving it a value when used.
            (closes vim#10088)

patch 8.2.4697: Vim9: crash when adding a duplicate key to a dictionary

Problem:    Vim9: crash when adding a duplicate key to a dictionary.
Solution:   Clear the stack item when it has been moved into the dictionary.
            (closes vim#10087)

patch 8.2.4696: delete() with "rf" argument does not report a failure

Problem:    delete() with "rf" argument does not report a failure.
Solution:   Return -1 if the directory could not be removed. (closes vim#10078)

patch 8.2.4695: JSON encoding could be faster

Problem:    JSON encoding could be faster.
Solution:   Optimize encoding JSON strings. (closes vim#10086)

patch 8.2.4694: avoidance of #elif causes more preproc nesting

Problem:    Avoidance of #elif causes more preproc nesting.
Solution:   Use #elif where it is useful. (Ozaki Kiichi, closes vim#10081)

patch 8.2.4693: new regexp does not accept pattern "\%>0v"

Problem:    new regexp does not accept pattern "\%>0v".
Solution:   Do accept digit zero.

patch 8.2.4692: no test for what 8.2.4691 fixes

Problem:    No test for what 8.2.4691 fixes.
Solution:   Add a test.  Use a more generic sotlution. (closes vim#10090)