When the LHS is an lvalue/assignable tuple and there is no leading
sequence of binary expressions.
It's a bit hacky right now since we don't have a good way to
differentiate general pattern completions from builtin operators.
rdar://problem/23209683
Implement == and != for tuples up to arity 6 where each component type
is Equatable.
Implement <, <=, >, and >= for tuples up to arity 6 where each component
type is Comparable.
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
