[Sema] Set pattern on failure in typeCheckBinding

I don't think this currently affects anything, but match what we do
for the expression and update the pattern if type-checking the
initialization fails.

Author: hamishknight

lib/Sema/TypeCheckConstraints.cpp

@@ -854,6 +854,7 @@ bool TypeChecker::typeCheckBinding(Pattern *&pattern, Expr *&initializer,
 
   auto &Context = DC->getASTContext();
   initializer = target.getAsExpr();
+  pattern = target.getInitializationPattern();
 
   if (!initializer->getType())
     initializer->setType(ErrorType::get(Context));