exp() of Complex{BFloat16} get infinite recursion

[Centauria]

exp() of Complex{BFloat16} gets error

julia> exp(Complex{BFloat16}(0.0, 1.0))
Warning: detected a stack overflow; program state may be corrupted, so further execution might be unreliable.
ERROR: StackOverflowError:
Stacktrace:
     [1] sincos(x::BFloat16)
       @ Base.Math .\special\trig.jl:208
     [2] _sincos(x::BFloat16)
       @ Base.Math .\special\trig.jl:205
--- the above 2 lines are repeated 39990 more times ---
 [79983] sincos(x::BFloat16)
       @ Base.Math .\special\trig.jl:208

I made a patch and it works

Base.Math.sincos(x::BFloat16) = BFloat16.(sincos(Float32(x)))

but it's surely not the best approach.

Hope fixing.