Inference failure in `maximum` / `minimum`

[mcabbott]

Should this be able to infer the type?

julia> @inferred maximum([1 2; 3 4]; dims=1)
ERROR: return type Matrix{Int64} does not match inferred return type Union{Matrix{Float64}, Matrix{Int64}}

The instability is in Base.reducedim_init(identity, max, [1 2; 3 4], 1)

[N5N3]

Looks like a regression. There's no such instablity on 1.6.4.

[mcabbott]

Oh right, this one first appears on 1.7.

My initial example was this, which fails at least from 1.4 onwards:

@inferred Base.reducedim_init(norm, max, [1 2; 3 4], 1)

[N5N3]

eb47275 fix both cases on master.
But still don't know which cause the inference regression...
Edit: Well there's no inference regression, the instability was introduced by #35316.