(various) FunctionType::get's, ArrayType::get,
ArraySliceType::get, OptionalType::get, and a few
other places.
There is more to be done here, but this is all I plan to do
for now.
Swift SVN r11497
This shaves about 10% off the number of solution states explored when
type-checking the standard library, although it doesn't improve
overall time by much. In a more targeted benchmark, 1 + 2.0 + 1, we
get a 21% speedup.
Swift SVN r11033
