swift234

Substantially rework CSApply's building of argument lists for calls.

This fixes <rdar://problem/20494437> SILGen crash handling default arguments
again, and includes a fix for MiscDiagnostics to look through the generated
TupleShuffleExprs in @noescape processing (which tripped up XCTest).

This fixes <rdar://problem/16860940> QoI: Strict keyword arguments loses type sugar in calls
where we'd lose some type sugar.

This fixes sanity in the ASTs: ScalarToTupleExpr now always has consistent
types between its argument and result, so we can turn on AST Verification of it.




Swift SVN r27827