filter REPL backtraces on top-level scope instead of eval

[KristofferC]

Changes:

julia> error()
ERROR:
Stacktrace:
 [1] error() at ./error.jl:42
 [2] top-level scope

back to what it was on 0.6:

julia> error()
ERROR:
Stacktrace:
 [1] error() at ./error.jl:42

I'm not sure this is completely correct since I do not know exactly when the "top-level scope" frames appear.

cc @Keno

[yuyichao]

No this shouldn't be done. The toplevel scope is the repl.

[yuyichao]

julia> begin
       sin(1)
       error()
       end
ERROR:
Stacktrace:
 [1] error() at ./error.jl:44
 [2] top-level scope at REPL[1]:3

julia> error()
ERROR:
Stacktrace:
 [1] error() at ./error.jl:44
 [2] top-level scope

What can be done, of course, is to make sure the top-level scope in the second case also has line number.