Bugfix/expansion generic signature 2

[jaredlll08]

Remake of #122 due to accidental merging.

[jaredlll08]

@kindlich

You could add tests for the other means of creating arrays (both single, and multi-dimensional):

• Literal: var x = [1, 2, 3]

• Constructor with default value

  • 1D: var x = new int[](size, defaultValue); println(x[0]);
  • 2D: var x = new int[,](sizeA, sizeB, defaultValue); println(x[0,0]);

• Constructor with callback function var x = new int[](size, (index as usize) => {return 10 as int;}); println(x[0]);

• Constructor with projection function var x = [1, 2, 3] as int[]; var y = new int[](x, (valueFromX as int) => {return 2 * valueFromX;}); println(y[0]);

This PR now has tests for all cases besides the projection function, due to potentially incorrect implementation of the function itself, unrelated to this PR.

[kindlich]

Tests pass and #122 already had my approve 😉

[jaredlll08]

The missing tests have been fixed and added