Index: include/llvm/IR/LLVMContext.h
===================================================================
--- include/llvm/IR/LLVMContext.h
+++ include/llvm/IR/LLVMContext.h
@@ -60,7 +60,8 @@
     MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access"
     MD_nonnull = 11, // "nonnull"
     MD_dereferenceable = 12, // "dereferenceable"
-    MD_dereferenceable_or_null = 13 // "dereferenceable_or_null"
+    MD_dereferenceable_or_null = 13, // "dereferenceable_or_null"
+    MD_make_implicit = 14 // "make.implicit"
   };
 
   /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
Index: lib/CodeGen/ImplicitNullChecks.cpp
===================================================================
--- lib/CodeGen/ImplicitNullChecks.cpp
+++ lib/CodeGen/ImplicitNullChecks.cpp
@@ -38,6 +38,7 @@
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Instruction.h"
+#include "llvm/IR/LLVMContext.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
@@ -134,7 +135,7 @@
 
   MDNode *BranchMD =
       MBB.getBasicBlock()
-          ? MBB.getBasicBlock()->getTerminator()->getMetadata("make.implicit")
+          ? MBB.getBasicBlock()->getTerminator()->getMetadata(LLVMContext::MD_make_implicit)
           : nullptr;
   if (!BranchMD)
     return false;
Index: lib/IR/LLVMContext.cpp
===================================================================
--- lib/IR/LLVMContext.cpp
+++ lib/IR/LLVMContext.cpp
@@ -104,6 +104,12 @@
   assert(DereferenceableOrNullID == MD_dereferenceable_or_null && 
          "dereferenceable_or_null kind id drifted");
   (void)DereferenceableOrNullID;
+
+  // Create the 'make.implicit' metadata kind.
+  unsigned MakeImplicitID = getMDKindID("make.implicit");
+  assert(MakeImplicitID == MD_make_implicit &&
+         "make.implicit kind id drifted");
+  (void)MakeImplicitID;
 }
 LLVMContext::~LLVMContext() { delete pImpl; }