std.unicode: cleanup allocations on error in allocating functions
Fixes leaks when `utf16leToUtf8Alloc`/`utf16leToUtf8AllocZ`/`utf8ToUtf16LeWithNull` return an error and adds relevant test cases
db940a2c81Ryan Liptak committed on 9/16/2021, 9:43:07 AM· committed by Isaac Freundparente1bf350