There are two variants per angle type, so a total of four entries.
I used the same exact values for the multipliers as the ones in
Magnum::Math (utilizing Math::Constants<T>::pi()).
Added Float & Double overrides, so the other variants (Half & integer
variants) are effectively untouched.
Added Dot() & IsNormalized() intrinsic functions for each entry.
The reason we need separate entries for Float & Double is because the
epsilon values used for Dot() are different.
Epsilon values are taken directly from Magnum::Math::TypeTraits & they
are added to & subtracted from 1.0, in order to avoid using abs(), which
is prohibited in .natvis.