support: Fix -Wjump-misses-init build error in ios_file (GCC 16 / Win… (#62108)
…dows)
Under GCC 16 (e.g. mingw GCC 16.1.0), the Windows build of
src/support/ios.c failed to compile with:
error: jump skips variable initialization [-Werror=jump-misses-init]
In ios_file, the Windows (_OS_WINDOWS_) branch declared and initialized
locals (wlen and fname_w) after one or more `goto open_file_err`
statements. Those gotos could jump past the initialization of these auto
variables to the open_file_err label. This is non-conforming in C++ and
diagnosed by GCC's -Wjump-misses-init, which Julia promotes to a hard
error on Windows via -Wc++-compat -Werror. Older GCC in the previous
Windows image did not flag it; GCC 16 does.
Co-authored-by: Keno Fischer <Keno@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>