Hover offers wrong method definitions for `Core` functions

[aviatesk]

Hovering over typeof etc would result in:

... doc strings
### 2 methodsfor function Core.typeof
[1] typeof()
[2] typeof(x::Core.Any)

while typeof() doesn't exist

[ZacLN]

This is the culprit: https://github.com/julia-vscode/SymbolServer.jl/blob/master/src/symbols.jl#L346