Bug/numerical instability in exp/_exp returning NaN (for at least Float32); not in sync with Base/LinearAlgebra

[PallHaraldsson]

https://discourse.julialang.org/t/numeric-stability-of-base-exp-of-static-matrix-of-float32/133389

See: #785 (comment)

https://github.com/JuliaArrays/StaticArrays.jl/blame/a9333fa830d27b85d6c8aa284d32df1b6de0634f/src/expm.jl#L99-L101

exp in "Base" does basically:

exp!(copy_similar(A, eigtype(eltype(A))))

and calls comparable method (that has changed 11 months ago and 4 years ago):
https://github.com/JuliaLang/LinearAlgebra.jl/blame/8d79b34b0423e616dc2899e41299e36f5190bb82/src/dense.jl#L782C54-L782C54

[PallHaraldsson]

Dup of #1285 (also a dup) so closing here.