Index: include/llvm/IR/Instructions.h
===================================================================
--- include/llvm/IR/Instructions.h
+++ include/llvm/IR/Instructions.h
@@ -838,6 +838,8 @@
   Type *SourceElementType;
   Type *ResultElementType;
 
+  void anchor() override;
+
   GetElementPtrInst(const GetElementPtrInst &GEPI);
   void init(Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr);
 
@@ -1096,6 +1098,8 @@
 /// must be identical types.
 /// \brief Represent an integer comparison operator.
 class ICmpInst: public CmpInst {
+  void anchor() override;
+
   void AssertOK() {
     assert(getPredicate() >= CmpInst::FIRST_ICMP_PREDICATE &&
            getPredicate() <= CmpInst::LAST_ICMP_PREDICATE &&
@@ -2409,6 +2413,8 @@
 // scientist's overactive imagination.
 //
 class PHINode : public Instruction {
+  void anchor() override;
+
   void *operator new(size_t, unsigned) = delete;
   /// ReservedSpace - The number of operands actually allocated.  NumOperands is
   /// the number actually in use.
Index: lib/IR/Instructions.cpp
===================================================================
--- lib/IR/Instructions.cpp
+++ lib/IR/Instructions.cpp
@@ -87,6 +87,8 @@
 //                               PHINode Class
 //===----------------------------------------------------------------------===//
 
+void PHINode::anchor() {}
+
 PHINode::PHINode(const PHINode &PN)
     : Instruction(PN.getType(), Instruction::PHI, nullptr, PN.getNumOperands()),
       ReservedSpace(PN.getNumOperands()) {
@@ -1622,6 +1624,8 @@
 //                       GetElementPtrInst Implementation
 //===----------------------------------------------------------------------===//
 
+void GetElementPtrInst::anchor() {}
+
 void GetElementPtrInst::init(Value *Ptr, ArrayRef<Value *> IdxList,
                              const Twine &Name) {
   assert(getNumOperands() == 1 + IdxList.size() &&
@@ -3506,6 +3510,8 @@
   }
 }
 
+void ICmpInst::anchor() {}
+
 ICmpInst::Predicate ICmpInst::getSignedPredicate(Predicate pred) {
   switch (pred) {
     default: llvm_unreachable("Unknown icmp predicate!");