Recently an internal compiler error has been popping up for folks
stemming from our MatBase matrix `operator<<`.
My guess is that the nested fold-expression (coming from `unroll`) and
the lambda is causing MSVC to become very upset in some instances.
Regardless of the actual cause, using simple for loops results in less
generated code and the use of `unroll` isn't required since these output
operators are mainly for debugging.
Unfortunately I've been unable to reproduce it in simpler contexts to
report it upstream.
Pull Request: https://projects.blender.org/blender/blender/pulls/119982
b37e825d89