some deprecated methods in the wrong module

[JeffBezanson]

E.g. the vectorized method of acos_fast is in Base instead of FastMath. Caused by 7ec9b18. cc @vtjnash

I believe this is because in

macro dep_vectorize_1arg(S, f)
    x = esc(:x) # work around macro hygiene bug
    T = esc(:T) # work around macro hygiene bug
    return :( @deprecate $f($x::AbstractArray{$T}) where {$T<:$S} $f.($x) )
end

since f refers to a raw symbol, the $f is now looked up in the definition environment of the macro, which is Base. I tried to fix it by adding back f = esc(f), but the @deprecate macro doesn't like that. I usually end up with:

LoadError("sysimg.jl", 416, LoadError("deprecated.jl", 263, ErrorException("syntax: malformed \"export\" statement")))

or

LoadError("sysimg.jl", 416, LoadError("deprecated.jl", 151, ErrorException("syntax: invalid syntax (escape (outerref isambiguous))")))

I suspect both are due to not allowing multiple levels of esc wrapping.

[yuyichao]

Possibly related?

julia> module A
       """
       doc
       """
       f() = 1
       export f
       end
A

julia> using A

help?> f
search: f fd for fma fld fft full fld1 find filt fill fft! fdio frexp foldr foldl flush floor float first findn filt! fill! fetch FFTW fldmod findnz findin filter falses finally foreach flipdim fldmod1

  doc

help?> A.f
ERROR: UndefVarError: A not defined

Also, Compat.@dep_vectorize_* are broken.

[JeffBezanson]

Implementing more of #10940 might be the way to go here. Basically, I think the most intuitive thing is to leave raw symbols alone as much as possible. If you put :x in an expression, the eventual output after expansion will just contain :x. Another way to look at it is that this makes the caller scope the "default", which is good because you can understand macros to a large degree by visualizing the macro output pasted at the call site.

Of course that means when a macro calls another macro, it can see (hygienic x) expressions, but something like that is probably unavoidable, and this feels like it moves the complexity to the right place.