patch 8.2.1712: Vim9: leaking memory when calling a lambda

Problem:    Vim9: leaking memory when calling a lambda.
Solution:   Decrement function reference from ISN_DCALL.

patch 8.2.1711: Vim9: leaking memory when using partial

Problem:    Vim9: leaking memory when using partial.
Solution:   Do delete the function even when it was compiled.

patch 8.2.1710: Vim9: list of list type can be wrong

Problem:    Vim9: list of list type can be wrong.
Solution:   Use VAR_UNKNOWN for empty list.  Recognize VAR_UNKNOWN when
            looking for a common type. (closes vim#6979)

patch 8.2.1709: Vim9: memory leak when using multiple closures

Problem:    Vim9: memory leak when using multiple closures.
Solution:   Free the partial.

patch 8.2.1708: Vim9: error message for function has unpritable chara…

…cters

Problem:    Vim9: error message for function has unpritable characters.
Solution:   use printable_func_name(). (closes vim#6965)

patch 8.2.1707: small inconsitency in highlight test

Problem:    Small inconsitency in highlight test.
Solution:   Use one argument for :execute. (Antony Scriven, vim#6975)

patch 8.2.1706: Vim9: crash after running into the "Multiple closures…

…" error

Problem:    Vim9: crash after running into the "Multiple closures" error.
Solution:   When a function fails still update any closures. (closes vim#6973)

patch 8.2.1705: "verbose hi Name" reports incorrect info after ":hi c…

…lear"

Problem:    "verbose hi Name" reports incorrect info after ":hi clear".
Solution:   Store the script context. (Antony Scriven, closes vim#6975)

patch 8.2.1704: Vim9: crash in for loop when autoload script has an e…

…rror

Problem:    Vim9: crash in for loop when autoload script has an error.
Solution:   Reset suppress_errthrow.  Check for NULL list. (closes vim#6967)

patch 8.2.1703: ":highlight clear" does not restore default link

Problem:    ":highlight clear" does not restore default link.
Solution:   Remember the default link and restore it. (Antony Scriven,
            closes vim#6970, closes vim#4405)