diff --git a/llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h b/llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h
--- a/llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h
+++ b/llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h
@@ -149,6 +149,28 @@
   /// This method is called from finalizeMemory.
   virtual void invalidateInstructionCache();
 
+  // Trivial implementation of SectionMemoryManager::MemoryMapper that just
+  // calls into sys::Memory.
+  class DefaultMMapper final : public SectionMemoryManager::MemoryMapper {
+  public:
+    sys::MemoryBlock
+    allocateMappedMemory(SectionMemoryManager::AllocationPurpose Purpose,
+                         size_t NumBytes,
+                         const sys::MemoryBlock *const NearBlock,
+                         unsigned Flags, std::error_code &EC) override {
+      return sys::Memory::allocateMappedMemory(NumBytes, NearBlock, Flags, EC);
+    }
+
+    std::error_code protectMappedMemory(const sys::MemoryBlock &Block,
+                                        unsigned Flags) override {
+      return sys::Memory::protectMappedMemory(Block, Flags);
+    }
+
+    std::error_code releaseMappedMemory(sys::MemoryBlock &M) override {
+      return sys::Memory::releaseMappedMemory(M);
+    }
+  };
+
 private:
   struct FreeMemBlock {
     // The actual block of free memory
@@ -186,6 +208,7 @@
   MemoryGroup RWDataMem;
   MemoryGroup RODataMem;
   MemoryMapper &MMapper;
+  DefaultMMapper DefaultMMapperInstance;
 };
 
 } // end namespace llvm
diff --git a/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp b/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp
--- a/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp
+++ b/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp
@@ -242,31 +242,6 @@
 
 void SectionMemoryManager::anchor() {}
 
-namespace {
-// Trivial implementation of SectionMemoryManager::MemoryMapper that just calls
-// into sys::Memory.
-class DefaultMMapper final : public SectionMemoryManager::MemoryMapper {
-public:
-  sys::MemoryBlock
-  allocateMappedMemory(SectionMemoryManager::AllocationPurpose Purpose,
-                       size_t NumBytes, const sys::MemoryBlock *const NearBlock,
-                       unsigned Flags, std::error_code &EC) override {
-    return sys::Memory::allocateMappedMemory(NumBytes, NearBlock, Flags, EC);
-  }
-
-  std::error_code protectMappedMemory(const sys::MemoryBlock &Block,
-                                      unsigned Flags) override {
-    return sys::Memory::protectMappedMemory(Block, Flags);
-  }
-
-  std::error_code releaseMappedMemory(sys::MemoryBlock &M) override {
-    return sys::Memory::releaseMappedMemory(M);
-  }
-};
-
-DefaultMMapper DefaultMMapperInstance;
-} // namespace
-
 SectionMemoryManager::SectionMemoryManager(MemoryMapper *MM)
     : MMapper(MM ? *MM : DefaultMMapperInstance) {}