Compiler: correctly pass named arguments for previous_def and super

[asterite]

Fixes https://forum.crystal-lang.org/t/i-may-have-found-a-bug-with-previous-def-but-not-sure/2624/2

The way the compiler handles super and previous_def without parentheses is by copying the current method's arguments to the call. So for example:

def foo(x, y)
  previous_def
end

gets expanded to:

def foo(x, y)
  previous_def(x, y)
end

The logic also took into account splats. This:

def foo(x, *y)
  previous_def
end

was expanded to:

def foo(x, *y)
  previous_def(x, *y)
end

However, arguments past the splat were passed as regular arguments. So this:

def foo(x, *y, z)
  previous_def
end

was incorrectly expanded to:

def foo(x, *y, z)
  previous_def(x, *y, z)
end

which wouldn't compile, unless z had a default value (it does in the bug report).

This PR changes the above expansion to be:

def foo(x, *y, z)
  previous_def(x, *y, z: z)
end

[jgaskins]

However, arguments past the splat were passed as regular arguments. So this:

def foo(x, *y, z)
  previous_def
end

was incorrectly expanded to:

def foo(x, *y, z)
  previous_def(x, *y, z)
end

which wouldn't compile, unless z had a default value (it does in the bug report).

I'm learning a lot about splat args from this PR. Thank you so much for your effort! 💯