Sema: Assert that bridging constraints aren't formed when ObjC interop is disabled.

Author: jckarter

lib/Sema/CSSimplify.cpp

@@ -3351,9 +3351,10 @@ ConstraintSystem::simplifyBridgingConstraint(Type type1,
                                              Type type2,
                                              TypeMatchOptions flags,
                                              ConstraintLocatorBuilder locator) {
-  // There's no bridging without ObjC interop.
-  if (!TC.Context.LangOpts.EnableObjCInterop)
-    return SolutionKind::Error;
+  // There's no bridging without ObjC interop, so we shouldn't have set up
+  // bridging constraints without it.
+  assert(TC.Context.LangOpts.EnableObjCInterop
+         && "bridging constraint w/o ObjC interop?!");
 
   TypeMatchOptions subflags = getDefaultDecompositionOptions(flags);
 

lib/Sema/Constraint.cpp

@@ -527,6 +527,10 @@ Constraint *Constraint::create(ConstraintSystem &cs, ConstraintKind kind,
           kind != ConstraintKind::LiteralConformsTo &&
           kind != ConstraintKind::SelfObjectOfProtocol) ||
          second->is<ProtocolType>());
+  
+  // Bridging constraints require bridging to be enabled.
+  assert(kind != ConstraintKind::BridgingConversion
+         || cs.TC.Context.LangOpts.EnableObjCInterop);
 
   // Create the constraint.
   unsigned size = totalSizeToAlloc<TypeVariableType*>(typeVars.size());