Japanese input broken with glib 2.56 on Windows 32-bit

That's quite a specific mix, but here is what we got reported on GIMP: on Windows 32-bit, with the Japanese IME, they cannot input the letters from the keyboard mapping (so mostly ASCII), even though in ASCII mode.

When downgrading only the glib DLL to glib 2.54.3, the bug is fixed.

For details, see: gimp#1603 (closed)