swift234

More effectively simplify constraint graphs for nested binary expressions with homogeneous argument types. For example, this allows us to typecheck expressions of the form "a + b + c + d", where each variable is of an array type, without getting a "too complex" error.

Note that the typecheck perf for these kinds of expressions still isn't fantastic, but at least they're now computationally feasible. I have further improvements planned for this area which should bring performance in line with expectations.