Index: include/clang/AST/Expr.h
===================================================================
--- include/clang/AST/Expr.h
+++ include/clang/AST/Expr.h
@@ -2821,7 +2821,6 @@
               (op && op->containsUnexpandedParameterPack()))),
         Op(op) {
     CastExprBits.Kind = kind;
-    CastExprBits.PartOfExplicitCast = false;
     setBasePathSize(BasePathSize);
     assert(CastConsistency());
   }
@@ -2836,13 +2835,6 @@
   CastKind getCastKind() const { return (CastKind) CastExprBits.Kind; }
   void setCastKind(CastKind K) { CastExprBits.Kind = K; }
 
-  bool getIsPartOfExplicitCast() const {
-    return CastExprBits.PartOfExplicitCast;
-  }
-  void setIsPartOfExplicitCast(bool PartOfExplicitCast) {
-    CastExprBits.PartOfExplicitCast = PartOfExplicitCast;
-  }
-
   static const char *getCastKindName(CastKind CK);
   const char *getCastKindName() const { return getCastKindName(getCastKind()); }
 
@@ -2917,18 +2909,29 @@
 private:
   ImplicitCastExpr(QualType ty, CastKind kind, Expr *op,
                    unsigned BasePathLength, ExprValueKind VK)
-    : CastExpr(ImplicitCastExprClass, ty, VK, kind, op, BasePathLength) {
+      : CastExpr(ImplicitCastExprClass, ty, VK, kind, op, BasePathLength) {
+    CastExprBits.PartOfExplicitCast = false;
   }
 
   /// Construct an empty implicit cast.
   explicit ImplicitCastExpr(EmptyShell Shell, unsigned PathSize)
-    : CastExpr(ImplicitCastExprClass, Shell, PathSize) { }
+      : CastExpr(ImplicitCastExprClass, Shell, PathSize) {
+    CastExprBits.PartOfExplicitCast = false;
+  }
 
 public:
   enum OnStack_t { OnStack };
   ImplicitCastExpr(OnStack_t _, QualType ty, CastKind kind, Expr *op,
                    ExprValueKind VK)
-    : CastExpr(ImplicitCastExprClass, ty, VK, kind, op, 0) {
+      : CastExpr(ImplicitCastExprClass, ty, VK, kind, op, 0) {
+    CastExprBits.PartOfExplicitCast = false;
+  }
+
+  bool getIsPartOfExplicitCast() const {
+    return CastExprBits.PartOfExplicitCast;
+  }
+  void setIsPartOfExplicitCast(bool PartOfExplicitCast) {
+    CastExprBits.PartOfExplicitCast = PartOfExplicitCast;
   }
 
   static ImplicitCastExpr *Create(const ASTContext &Context, QualType T,
Index: include/clang/AST/Stmt.h
===================================================================
--- include/clang/AST/Stmt.h
+++ include/clang/AST/Stmt.h
@@ -198,6 +198,7 @@
 
   class CastExprBitfields {
     friend class CastExpr;
+    friend class ImplicitCastExpr;
 
     unsigned : NumExprBits;
 
Index: lib/AST/ASTDumper.cpp
===================================================================
--- lib/AST/ASTDumper.cpp
+++ lib/AST/ASTDumper.cpp
@@ -521,6 +521,7 @@
     // Exprs
     void VisitExpr(const Expr *Node);
     void VisitCastExpr(const CastExpr *Node);
+    void VisitImplicitCastExpr(const ImplicitCastExpr *Node);
     void VisitDeclRefExpr(const DeclRefExpr *Node);
     void VisitPredefinedExpr(const PredefinedExpr *Node);
     void VisitCharacterLiteral(const CharacterLiteral *Node);
@@ -2117,7 +2118,10 @@
   }
   dumpBasePath(OS, Node);
   OS << ">";
+}
 
+void ASTDumper::VisitImplicitCastExpr(const ImplicitCastExpr *Node) {
+  VisitCastExpr(Node);
   if (Node->getIsPartOfExplicitCast())
     OS << " part_of_explicit_cast";
 }
Index: lib/Sema/SemaCast.cpp
===================================================================
--- lib/Sema/SemaCast.cpp
+++ lib/Sema/SemaCast.cpp
@@ -94,7 +94,7 @@
       // ImplicitCastExpr's as being part of ExplicitCastExpr. The original CE
       // (which is a ExplicitCastExpr), and the OrigSrcExpr are not touched.
       while ((CE = dyn_cast<ImplicitCastExpr>(CE->getSubExpr())))
-        CE->setIsPartOfExplicitCast(true);
+        dyn_cast<ImplicitCastExpr>(CE)->setIsPartOfExplicitCast(true);
     }
 
     /// Complete an apparently-successful cast operation that yields
Index: lib/Serialization/ASTReaderStmt.cpp
===================================================================
--- lib/Serialization/ASTReaderStmt.cpp
+++ lib/Serialization/ASTReaderStmt.cpp
@@ -723,7 +723,6 @@
   assert(NumBaseSpecs == E->path_size());
   E->setSubExpr(Record.readSubExpr());
   E->setCastKind((CastKind)Record.readInt());
-  E->setIsPartOfExplicitCast(Record.readInt());
   CastExpr::path_iterator BaseI = E->path_begin();
   while (NumBaseSpecs--) {
     auto *BaseSpec = new (Record.getContext()) CXXBaseSpecifier;
@@ -770,6 +769,7 @@
 
 void ASTStmtReader::VisitImplicitCastExpr(ImplicitCastExpr *E) {
   VisitCastExpr(E);
+  E->setIsPartOfExplicitCast(Record.readInt());
 }
 
 void ASTStmtReader::VisitExplicitCastExpr(ExplicitCastExpr *E) {
Index: lib/Serialization/ASTWriterStmt.cpp
===================================================================
--- lib/Serialization/ASTWriterStmt.cpp
+++ lib/Serialization/ASTWriterStmt.cpp
@@ -665,7 +665,6 @@
   Record.push_back(E->path_size());
   Record.AddStmt(E->getSubExpr());
   Record.push_back(E->getCastKind()); // FIXME: stable encoding
-  Record.push_back(E->getIsPartOfExplicitCast());
 
   for (CastExpr::path_iterator
          PI = E->path_begin(), PE = E->path_end(); PI != PE; ++PI)
@@ -714,6 +713,7 @@
 
 void ASTStmtWriter::VisitImplicitCastExpr(ImplicitCastExpr *E) {
   VisitCastExpr(E);
+  Record.push_back(E->getIsPartOfExplicitCast());
 
   if (E->path_size() == 0)
     AbbrevToUse = Writer.getExprImplicitCastAbbrev();