Problem:    When indenting gets out of hand it is hard to stop.
Solution:   When line gets too long set got_int.

Problem:    DirChanged autocommand may use freed memory. (Shane-XB Qian)
Solution:   Free the memory later. (closes #10555)

Problem:    Substitute test has a one second delay.
Solution:   Use ":silent!".  Add another test case. (closes #10558)

Problem:    Various warnings from clang on MS-Windows.
Solution:   Avoid the warnings. (Yegappan Lakshmanan, closes #10553)

Problem:    Unnecessary code.
Solution:   Remove code and replace with function call. (closes #10552)

Problem:    Clang gives an out of bounds warning.
Solution:   adjust conditional expression (John Marriott)

Problem:    Spell test fails on MS-Windows.
Solution:   Do not change 'encoding'

Problem:    Clang on MS-Windows produces warnings.
Solution:   Avoid the warnings. (Yegappan Lakshmanan, closes #10546)

Problem:    Using uninitialized value and freed memory in spell command.
Solution:   Initialize "attr".  Check for empty line early.