dict.copy() result is not inferred as dict

[eugene57]

Steps to reproduce

Run this code:

import astroid

code = """
x = dict()
y = x.copy()
"""

ast = astroid.parse(code)

for name in ('x', 'y'):
  node = ast.locals[name][0]
  print(name, node.inferred())

Current behavior

x [<Dict.dict l.2 at 0x7fffe852e110>]
y [Uninferable]

Expected behavior

I expect y to be inferred as dict too.

python -c "from astroid import __pkginfo__; print(__pkginfo__.version)" output

2.4.2

[timmartin]

I think the same issue applies to list, set and bytearray. I think we can deal with all these at the same time.