Use an early exit in DIBuilder::finalize() to improve readability.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241465 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/DIBuilder.cpp

@@ -73,7 +73,12 @@ void DIBuilder::trackIfUnresolved(MDNode *N) {
 }
 
 void DIBuilder::finalize() {
-  if (CUNode) {
+  if (!CUNode) {
+    assert(!AllowUnresolvedNodes &&
+           "creating type nodes without a CU is not supported");
+    return;
+  }
+
   CUNode->replaceEnumTypes(MDTuple::get(VMContext, AllEnumTypes));
 
   SmallVector<Metadata *, 16> RetainValues;
@@ -103,7 +108,6 @@ void DIBuilder::finalize() {
   CUNode->replaceImportedEntities(MDTuple::get(
       VMContext, SmallVector<Metadata *, 16>(AllImportedModules.begin(),
                                              AllImportedModules.end())));
-  }
 
   // Now that all temp nodes have been replaced or deleted, resolve remaining
   // cycles.