P5.js: avoid use of arguments in square()

[outofambit]

brought up in #3525 and https://github.com/processing/p5.js/pull/3531#issuecomment-466808663

such use of the arguments array causes deoptimization in many js jits

alternate implementation proposed by @Spongman :

p5.prototype.square = function(x, y, s, tl, tr, br, bl) {
  this.rect(x, y, s, s, tl, tr, br, bl);
};

this should be more performant than the current implementation (which uses arguments).

https://github.com/processing/p5.js/blob/571bd7a52ae7afdb056cfc0b9ea53927514f507c/src/core/shape/2d_primitives.js#L517-L522

[Spongman]

just to expand on this: in general whenever the arguments object is mutated, or passed to a method (except as the 2nd argument of function.apply) the runtime has to copy the stack-allocated arguments object to a heap-allocated, garbage collected temporary proxy object. additionally, the added complexity of this often can result in the method no longer being eligible for native code generation.

[ihsavru]

I'd like to work on this