Remove the ability to access the "0" member of a scalar.

This is a travesty that makes it hard to reason about tuple vs. scalar
types. It's only use in our own code involved dealing with the
difference in element types between Set and Dictionary in
gyb-generated code. Ewww. Fixes rdar://problem/17963034.

Swift SVN r30074

lib/Sema/CSSimplify.cpp

@@ -3047,14 +3047,6 @@ ConstraintSystem::simplifyMemberConstraint(const Constraint &constraint) {
     Type rawValueType;
     if (name.isSimpleName()
         && !name.getBaseName().str().getAsInteger(10, index)) {
-      // ".0" on a scalar just refers to the underlying scalar value.
-      if (index == 0) {
-        OverloadChoice identityChoice(baseTy, OverloadChoiceKind::BaseType);
-        addBindOverloadConstraint(memberTy, identityChoice,
-                                  constraint.getLocator());
-        return SolutionKind::Solved;
-      }
-
       recordFailure(constraint.getLocator(), Failure::DoesNotHaveMember,
                     baseObjTy, name);