swift234

SILGen: Handle scalar-to-tuple shuffles in function arguments.

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