Previously, we were comparing the signed int `target_length` (returned by WideCharToMultiByte) to a size_t string length, resulting in a signed/unsigned comparison warning as follows:
```
windows\runner\utils.cpp(54,43): warning C4018: '>': signed/unsigned mismatch
```
WideCharToMultiByte returns:
* 0 on error
* the number of bytes written to the buffer pointed to by its fifth parameter, lpMultiByteStr, on success.
As a result it's safe to store the return value in an unsigned int, which eliminates the warning.
No changes to tests since this is dependent on end-user project settings/modifications and does not trigger a warning with default project settings.
Fixes: https://github.com/flutter/flutter/issues/134227
This patch adds an additional check to ensure the target length of a string is within the supported maximum string length prior to calling WideCharToMultiByte/MultiByteToWideChar in the Windows runner template.
This is to prevent resize() from failing if called with a count > std::string::max_size().
According to Win32 API docs (WideCharToMultiByte, MultiByteToWideChar) it's the caller responsibility to make sure the buffers are correctly allocated.
Authored by: Tomasz Gucio <tgucio@gmail.com>
