vim: Import v8.2.3516

* 8.2.3516: terminal window does not have transparent background
* 8.2.3515: nano time test fails on Mac and FreeBSD
* 8.2.3514: autoread test with nano second time sometimes fails
* 8.2.3513: using freed memory when using a timer and searching
* 8.2.3512: timestamp test fails on some systems
* 8.2.3511: Vim9: entry for loop variable is created every round

Author: chrisbra

gitlog.txt

@@ -1 +1 @@
-* [8.2.3510](https://github.com/vim/vim/commit/0a7984af5601323fae7b3398f05a48087db7b767): changes are only detected with one second accuracy\n* [8.2.3509](https://github.com/vim/vim/commit/340dd0fbe462a15a9678cfba02085b4adcc45f02): undo file is not synced\n* [8.2.3508](https://github.com/vim/vim/commit/051a8a375f8fb6a931fbc5ccca714a200d9b327f): Vim9: bad separators for "g" and "s" insufficiently tested\n* [8.2.3507](https://github.com/vim/vim/commit/75aa92a16264e3511ba41aa306ffc1ffbbd2fe3a): generating proto files may fail
+* [8.2.3516](https://github.com/vim/vim/commit/7b5f45be2197403d631b5a3d633f6a20afdf806e): terminal window does not have transparent background\n* [8.2.3515](https://github.com/vim/vim/commit/def69dffb3d09a69629b071c89b7893a1783ba53): nano time test fails on Mac and FreeBSD\n* [8.2.3514](https://github.com/vim/vim/commit/eaa006dae3d5730e3b6dead27905444998b2cf8e): autoread test with nano second time sometimes fails\n* [8.2.3513](https://github.com/vim/vim/commit/a2cff1dbc9c58758977eba3034603e6fe459031b): using freed memory when using a timer and searching\n* [8.2.3512](https://github.com/vim/vim/commit/accf4ed352c07ffe59022377c42d36e12dd6d461): timestamp test fails on some systems\n* [8.2.3511](https://github.com/vim/vim/commit/a06758dd38851f022d270dd5102efbe1049d4712): Vim9: entry for loop variable is created every round