[BUG] Invalid binding generation for union with long double field

I hit this issue due to a transitive dependency on bindgen 0.70 being bumped to 0.71 (and later 0.72.1):

• #2159

I don't really know what changed in recent versions that could lead to this, but I first got the transitive dependency bumped to 0.72.1 to get the fix for:

• #3264

Which did not fix my mingw-w64 CI fail.

• raylib in v5.5+ depends on bindgen 0.70 which did not surface the problem
• raylib v6.0.0-rc.2 bumped bindgen to 0.71, which suffers from
  • #3264
  • I tried bumping to 0.72.1 to get the fix to #3264, but this problem did not go away
    Using opaque_type or blocklist_type fixed it.

x86_64-w64-mingw32-gcc --version
x86_64-w64-mingw32-gcc (GCC) 16.1.0

clang --version
clang version 22.1.5

Start by reproducing the mingw-w64 CI failure with the reported bindgen, raylib, GCC, and Clang versions, then compare generated bindings across bindgen 0.70, 0.71, and 0.72.1. Done means the union containing a long double field generates valid bindings without requiring opaque_type or blocklist_type.