Base: make TwicePrecision more accurate using standard algorithms

[nsajko]

Update the arithmetic code to use algorithms published since
twiceprecision.jl got written.

Handle complex numbers.

Prevent some harmful promotions.

Some of the introduced extended precision arithmetic code will also be
used in base/div.jl to tackle issue #49450 with PR #49561.

Results:

The example in #33677 still gives the same result.

I wasn't able to evaluate #23497 because of how much Julia changed in
the meantime.

Proof that #26553 is fixed:

julia> const TwicePrecision = Base.TwicePrecision
Base.TwicePrecision

julia> a = TwicePrecision{Float64}(0.42857142857142855, 2.3790493384824782e-17)
Base.TwicePrecision{Float64}(0.42857142857142855, 2.3790493384824782e-17)

julia> b = TwicePrecision{Float64}(3.4, 8.881784197001253e-17)
Base.TwicePrecision{Float64}(3.4, 8.881784197001253e-17)

julia> a_minus_b_inexact = Tuple(a - b)
(-2.9714285714285715, 1.0150610510858574e-16)

julia> BigFloat(a) == sum(map(BigFloat, Tuple(a)))
true

julia> BigFloat(b) == sum(map(BigFloat, Tuple(b)))
true

julia> a_minus_b = BigFloat(a) - BigFloat(b)
-2.971428571428571428571428571428577679589762353999797347402693647078382455095635

julia> Float64(a_minus_b) == first(a_minus_b_inexact)
true

julia> Float64(a_minus_b - Float64(a_minus_b)) == a_minus_b_inexact[begin + 1]
true

Fixes #26553

Updates #49589

[nsajko]

Note, in case this PR results in some unacceptable performance regression: it's possible to replace Algorithm 18 from the paper with Algorithm 17. It's less accurate but faster.

[nsajko]

A thing I'm still not certain about is division: the Base.div12 code used that trick with normalizing the numerator and denominator using frexp to try to prevent overflow and underflow, and, of course, I kept with that and furthermore extended the trick to double-word floating-point. This required increasing the slopbits parameter for a test, though.

[KristofferC]

Since this is an implementation detail for float ranges it feels like PRs improving it's accuracy need to have corresponding tests for what fixes it corresponds to for these ranges. Otherwise, it's hard to understand the point of it.