Merge pull request #14993 from eeckstein/fix-demangler

demangler: fix crashes for malformed symbols

Author: eeckstein

lib/Demangling/Demangler.cpp

@@ -873,8 +873,7 @@ NodePointer Demangler::demangleLocalIdentifier() {
     NodePointer name = popNode();
     NodePointer result = createNode(Node::Kind::RelatedEntityDeclName,
                                     StringRef(&relatedEntityKind, 1));
-    result->addChild(name, *this);
-    return result;
+    return addChild(result, name);
   }
   NodePointer discriminator = demangleIndexAsNode();
   NodePointer name = popNode(isDeclName);
@@ -2250,9 +2249,9 @@ NodePointer Demangler::demangleSpecialType() {
       auto name = popNode(Node::Kind::Identifier);
       auto parent = popContext();
       auto anon = createNode(Node::Kind::AnonymousContext);
-      anon->addChild(name, *this);
-      anon->addChild(parent, *this);
-      anon->addChild(types, *this);
+      anon = addChild(anon, name);
+      anon = addChild(anon, parent);
+      anon = addChild(anon, types);
       return anon;
     }
     case 'e':

test/Demangle/Inputs/manglings.txt

@@ -308,3 +308,5 @@ _T0So11CrappyColorVs16RawRepresentableSCMA --> reflection metadata associated ty
 $S28protocol_conformance_records15NativeValueTypeVAA8RuncibleAAMc --> protocol conformance descriptor for protocol_conformance_records.NativeValueType : protocol_conformance_records.Runcible in protocol_conformance_records
 $SSC9SomeErrorLeVD ---> __C_Synthesized.related decl 'e' for SomeError
 $S20mangling_retroactive5test0yyAA1ZVy12RetroactiveB1XVSiAE1YVAG0D1A1PAAg_AiJ1QAAg1_GF -> mangling_retroactive.test0(mangling_retroactive.Z<RetroactiveB.X, Swift.Int, RetroactiveB.Y>) -> ()
+_T0LiteralAByxGxd_tcfC ---> _T0LiteralAByxGxd_tcfC
+_T0XZ ---> _T0XZ