LineNumber nodes in :toplevel expressions are ignored

[stevengj]

LineNumber nodes can be used to add line numbers to a :block expression, but are ignored in :toplevel expressions:

julia> eval(Expr(:block, LineNumberNode(4, :foo), :(error("blah"))))
ERROR: blah
Stacktrace:
 [1] error(::String) at ./error.jl:33
 [2] top-level scope at foo:4                   #### ⟵ DESIRED LINE NUMBER
 [3] eval at ./boot.jl:319 [inlined]
 [4] eval(::Expr) at ./client.jl:399
 [5] top-level scope at none:0

julia> eval(Expr(:toplevel, LineNumberNode(4, :foo), :(error("blah"))))
ERROR: blah
Stacktrace:
 [1] error(::String) at ./error.jl:33
 [2] top-level scope at none:0                   ### ⟵ MISSING LINE NUMBER
 [3] eval at ./boot.jl:319 [inlined]
 [4] eval(::Expr) at ./client.jl:399
 [5] top-level scope at none:0

This seems like it makes it unnecessarily hard to add a line number when evaluating an arbitrary expression, because you can't put toplevel-only expressions (e.g. module or struct) inside :block expressions.

(This came up in addressing JuliaLang/SoftGlobalScope.jl#3.)

[JeffBezanson]

At the same time I notice [5] top-level scope at none:0, which is also wrong. This is a very long-standing bug; it should say [5] top-level scope at REPL[n]:1. I'll fix that too.