Top-level code doesn't have a catch context, and that's okay

Author: DougGregor

lib/AST/ASTVerifier.cpp

@@ -1025,16 +1025,14 @@ class Verifier : public ASTWalker {
       SourceLoc loc = S->getThrowLoc();
       if (loc.isValid()) {
         auto catchNode = ASTScope::lookupCatchNode(getModuleContext(), loc);
-
-        if (!catchNode) {
-          Out << "No catch context for throw statement\n";
-          abort();
-        }
-
-        if (auto thrown = catchNode.getThrownErrorTypeInContext(Ctx)) {
-          thrownError = *thrown;
+	if (catchNode) {
+          if (auto thrown = catchNode.getThrownErrorTypeInContext(Ctx)) {
+            thrownError = *thrown;
+          } else {
+            thrownError = Ctx.getNeverType();
+          }
         } else {
-          thrownError = Ctx.getNeverType();
+          thrownError = checkExceptionTypeExists("throw expression");
         }
       } else {
         return;