Fixed NxM matrix construction by
properly checking for these types in
TIntermOperator::isConstructor. Also
fixed a few areas of the code where
the secondary size wasn't properly
taken into account.

Change-Id: I646a41e37460255316f5712f1d744c3a06d8a64d
Reviewed-on: https://swiftshader-review.googlesource.com/3195Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>