New strict aliasing warnings in 2.83.7

[jengelh]

[   72s] /home/abuild/rpmbuild/BUILD/bullet3-2.83.7/src/Bullet3Collision/BroadPhaseCollision/b3DynamicBvh.cpp:42:36: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
[   72s]   b3DbvtVolume& res=*(b3DbvtVolume*)locals;
[   72s]                                     ^

This seems to be caused by:

#if (B3_DBVT_MERGE_IMPL==B3_DBVT_IMPL_SSE)
        B3_ATTRIBUTE_ALIGNED16(char locals[sizeof(b3DbvtAabbMm)]);
        b3DbvtVolume&   res=*(b3DbvtVolume*)locals;
#else

Reason: 1. (normally) the alignment of char is not guaranteed to be sufficient for b3DbvtVolume, 2. the compiler has not enough knowledge to establish that sizeof(b3DbvtVolume)<=sizeof(b3DbvtAabbMm). Perhaps the following is a better choice?

union storage_size_ensured {
    b3DbvtVolume v;
    char l[sizeof(b3DbvtAabbMm)] __attribute__((aligned((16)));
} locals;
b3DbvtVolume &res = locals.v;