Test fix.

Some tests depend on the bug fixed.
For example, the `convert` test for `NamedTuple` works because `Tuple{Type{NamedTuple{(:a,),Tuple{I}} where I<:Unsigned}} <: Tuple{Type{NT}} where {names, T<:Tuple, NT<:NamedTuple{names,T}}` on master.

Author: N5N3

base/namedtuple.jl

@@ -196,6 +196,14 @@ function convert(::Type{NT}, nt::NamedTuple{names}) where {names, T<:Tuple, NT<:
     return NT1(T1(nt))::NT1::NT
 end
 
+function convert(::Type{NT}, nt::NamedTuple{names}) where {names, NT<:NamedTuple{names}}
+    # converting abstract NT to an abstract Tuple type, to a concrete NT1, is not straightforward, so this could just be an error, but we define it anyways
+    # _tuple_error(NT, nt)
+    T1 = Tuple{ntuple(i -> fieldtype(NT, i), Val(length(names)))...}
+    NT1 = NamedTuple{names, T1}
+    return NT1(T1(nt))::NT1::NT
+end
+
 if nameof(@__MODULE__) === :Base
     Tuple(nt::NamedTuple) = (nt...,)
     (::Type{T})(nt::NamedTuple) where {T <: Tuple} = (t = Tuple(nt); t isa T ? t : convert(T, t)::T)

stdlib/LinearAlgebra/src/bidiag.jl

@@ -214,7 +214,7 @@ Matrix(A::Bidiagonal{T}) where {T} = Matrix{promote_type(T, typeof(zero(T)))}(A)
 Array(A::Bidiagonal) = Matrix(A)
 promote_rule(::Type{Matrix{T}}, ::Type{<:Bidiagonal{S}}) where {T,S} =
     @isdefined(T) && @isdefined(S) ? Matrix{promote_type(T,S)} : Matrix
-promote_rule(::Type{Matrix}, ::Type{<:Bidiagonal}) = Matrix
+promote_rule(::Type{<:Matrix}, ::Type{<:Bidiagonal}) = Matrix
 
 #Converting from Bidiagonal to Tridiagonal
 function Tridiagonal{T}(A::Bidiagonal) where T