swift234

teach typeCheckArgumentChildIndependently how to propagate type information 
down to call argument lists that have more than one operand (heavily leveraging
"computeTupleShuffle").  This resolves a great number of QoI radars, including
things like:
<rdar://problem/19981782> QoI: poor diagnostic for call to memcmp with UInt length parameter

where we used to produce:

error: cannot invoke 'memcmp' with an argument list of type '([UInt8], [UInt8], UInt)'
    return memcmp(left, right, UInt(left.count)) == 0
           ^
note: expected an argument list of type '(UnsafePointer<Void>, UnsafePointer<Void>, Int)'

but now we produce:
error: cannot convert value of type 'UInt' to expected argument type 'Int'
    return memcmp(left, right, UInt(left.count)) == 0
                               ^~~~~~~~~~~~~~~~

which is more "to the point"



Swift SVN r30930