Aggressive constprop in LinearAlgebra.wrap

[jishnub]

This helps with type-stability, as the flag tA is usually known from the type of the matrix.
On master,

julia> f(A) = LinearAlgebra.wrap(A, 'N')
f (generic function with 1 method)

julia> @code_typed f([1;;])
CodeInfo(
1 ─ %1 = invoke LinearAlgebra.wrap(A::Matrix{Int64}, 'N'::Char)::Union{Adjoint{Int64, Matrix{Int64}}, Hermitian{Int64, Matrix{Int64}}, Symmetric{Int64, Matrix{Int64}}, Transpose{Int64, Matrix{Int64}}, Matrix{Int64}}
└──      return %1
) => Union{Adjoint{Int64, Matrix{Int64}}, Hermitian{Int64, Matrix{Int64}}, Symmetric{Int64, Matrix{Int64}}, Transpose{Int64, Matrix{Int64}}, Matrix{Int64}}

This PR

julia> @code_typed f([1;;])
CodeInfo(
1 ─     return A
) => Matrix{Int64}

[dkarrasch]

Very much yes!!! I forgot about that opportunity. Would be interesting to see whether this also allows to remove the branches in the BLAS-version of generic_matmatmul!.