If a non-static 'let' field in a struct has an initializer, its implicitly generated
memberwise initializer should not override that. Handle this by having the memberwise initializer
and default initializer use the initial value of the property instead of an argument to the init.
This would have been a lot easier if sema was synthesizing the ctor bodies instead of SILGen,
but here it is. The missing case is narrow (let (x,y) = (1,2)) and for now we just disable
implicit synthesization of the incorrect case.
Swift SVN r25424
Previously the "as" keyword could either represent coercion or or forced
downcasting. This change separates the two notions. "as" now only means
type conversion, while the new "as!" operator is used to perform forced
downcasting. If a program uses "as" where "as!" is called for, we emit a
diagnostic and fixit.
Internally, this change removes the UnresolvedCheckedCastExpr class, in
favor of directly instantiating CoerceExpr when parsing the "as"
operator, and ForcedCheckedCastExpr when parsing the "as!" operator.
Swift SVN r24253
This decreases total testing time by over a minute on my old Mac Pro.
It probably has much less effect on systems with fewer cores, but shouldn't
be any worse there.
Swift SVN r22745
