MinGW: Use correct format specifier

[topolarity]

On my system, this cleans up all warnings when building Julia on Windows.

[giordano]

Does this mean we can use -Werror when compiling for windows on CI? 😈

Edit: no

In function '__readgsqword',
    inlined from 'jl_init_stack_limits' at C:/workdir/src/init.c:56:25:
C:/msys64/mingw64/include/psdk_inc/intrin-impl.h:838:1: warning: array subscript 0 is outside array bounds of 'long long unsigned int[0]' [-Warray-bounds]
  838 | __buildreadseg(__readgsqword, unsigned __int64, "gs", "q")
      | ^~~~~~~~~~~~~~

😢

[giordano]

Side note, related PR: #53764

[topolarity]

__readgsqword

That looks like https://sourceforge.net/p/mingw-w64/mailman/mingw-w64-public/thread/[email protected]/

Presumably a GCC bug that has since been fixed? I'm using 11.4.0 locally

[gitboy16]

I made a PR to fix a windows warning in utf8.c as well #54268
Please close all my PRs if this one fixes all windows warnings.