[Bug libstdc++/97484] typedef conflict for "byte" in GCC11 for MinGW-w64

[brechtsanders at users dot sourceforge.net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97484

--- Comment #3 from Brecht Sanders <brechtsanders at users dot sourceforge.net> ---
MinGW is pure C, so it doesn't use: using namespace std;
But I do see Ninja doing this before including windows.h.
However GCC 10 and older have no issue with this.
What changed in GCC 11 to cause the issue?