The rule changes are as follows:
* All functions (introduced with the 'func' keyword) have argument
labels for arguments beyond the first, by default. Methods are no
longer special in this regard.
* The presence of a default argument no longer implies an argument
label.
The actual changes to the parser and printer are fairly simple; the
rest of the noise is updating the standard library, overlays, tests,
etc.
With the standard library, this change is intended to be API neutral:
I've added/removed #'s and _'s as appropriate to keep the user
interface the same. If we want to separately consider using argument
labels for more free functions now that the defaults in the language
have shifted, we can tackle that separately.
Fixes rdar://problem/17218256.
Swift SVN r27704
Deferring to emitRValue doesn't work for inout parameters. Factor out the code for shuffling arguments in TupleShuffleExprs so we can reuse for ScalarToTuple transformations. Building what amounts to a fake TupleShuffle out of a ScalarToTuple isn't the most elegant solution, but I think it's the lowest-risk approach for the short term. Fixes rdar://problem/19814841.
Swift SVN r25290
