Cherry-pick upstream r237929

lib/AST/ItaniumMangle.cpp

Index: lib/AST/ItaniumMangle.cpp
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index 6e55655d85bba9678c445cb6b6446d5c1662fa49..0458cce64d86b3ac2c256e149e09512a082281fc 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -2884,9 +2884,9 @@ recurse:
 
   case Expr::UnresolvedMemberExprClass: {
     const UnresolvedMemberExpr *ME = cast<UnresolvedMemberExpr>(E);
-    mangleMemberExpr(ME->getBase(), ME->isArrow(),
-                     ME->getQualifier(), nullptr, ME->getMemberName(),
-                     Arity);
+    mangleMemberExpr(ME->isImplicitAccess() ? nullptr : ME->getBase(),
+                     ME->isArrow(), ME->getQualifier(), nullptr,
+                     ME->getMemberName(), Arity);
     if (ME->hasExplicitTemplateArgs())
       mangleTemplateArgs(ME->getExplicitTemplateArgs());
     break;
@@ -2895,8 +2895,9 @@ recurse:
   case Expr::CXXDependentScopeMemberExprClass: {
     const CXXDependentScopeMemberExpr *ME
       = cast<CXXDependentScopeMemberExpr>(E);
-    mangleMemberExpr(ME->getBase(), ME->isArrow(),
-                     ME->getQualifier(), ME->getFirstQualifierFoundInScope(),
+    mangleMemberExpr(ME->isImplicitAccess() ? nullptr : ME->getBase(),
+                     ME->isArrow(), ME->getQualifier(),
+                     ME->getFirstQualifierFoundInScope(),
                      ME->getMember(), Arity);
     if (ME->hasExplicitTemplateArgs())
       mangleTemplateArgs(ME->getExplicitTemplateArgs());