Fixes Clang warning on 32-bit platforms.
Clang is more strict about `-Wformat` than GCC. For `%I`, it expects the exact `size_t` type, which is `int` on 32-bit targets, while `SIZE_T` is `long`. For that reason, we currently disable those warnings by not using format attribute on MSVC targets. This is not enough for printf, which is a builtin and has the attribute applied anyway. Using trace, like we do in all other cases, "fixes" it.
I plan to make clang less strict about those cases, which would also fix this problem and allow us to enable format attribute in all relevant functions. However, on current versions of clang, this is one of the last few blockers to support `-Werror`, so it would be nice to have it fixed one way or another. If `printf` is preferred here for some reason, we could also just add an explicit `size_t` cast when printing the size.