Comment # 16 on bug 1201107 from Jan Engelhardt

i686-mingw-gcc10: section "/19" aka ".debug_info" looks like 

���������00003200 8e230000 04000000-00000401 474e5520 |?#  ?     ??GNU |              
���������00003210 43393920 31302e33-2e30202d 6d6d732d |C99 10.3.0 -mms-|              
���������00003220 62697466 69656c64-73202d6d 3332202d |bitfields -m32 -|              
���������00003230 6d74756e 653d6765-6e657269 63202d6d |mtune=generic -m|              

i686-mingw-gcc12: section looks like so

���������00003600 0a250000 05000104-00000000 35474e55 |?%  ? ??    5GNU|              
���������00003610 20433939 2031322e-312e3020 2d6d6d73 | C99 12.1.0 -mms|              
���������00003620 2d626974 6669656c-6473202d 6d333220 |-bitfields -m32 |              
���������00003630 2d6d7475 6e653d67-656e6572 6963202d |-mtune=generic -|              

Indeed, this is a version 4 CU vs. 5.