Index: lib/Linker/IRMover.cpp
===================================================================
--- lib/Linker/IRMover.cpp
+++ lib/Linker/IRMover.cpp
@@ -1023,14 +1023,15 @@
   for (unsigned I = 0, E = SrcCompileUnits->getNumOperands(); I != E; ++I) {
     auto *CU = cast<DICompileUnit>(SrcCompileUnits->getOperand(I));
     assert(CU && "Expected valid compile unit");
-    // Enums, macros, and retained types don't need to be listed on the
-    // imported DICompileUnit. This means they will only be imported
-    // if reached from the mapped IR. Do this by setting their value map
-    // entries to nullptr, which will automatically prevent their importing
+    // Enums, macros, retained types, and imported entities don't need to be
+    // listed on the imported DICompileUnit. This means they will only be
+    // imported if reached from the mapped IR. Do this by setting their value
+    // map entries to nullptr, which will automatically prevent their importing
     // when reached from the DICompileUnit during metadata mapping.
     ValueMap.MD()[CU->getRawEnumTypes()].reset(nullptr);
     ValueMap.MD()[CU->getRawMacros()].reset(nullptr);
     ValueMap.MD()[CU->getRawRetainedTypes()].reset(nullptr);
+    ValueMap.MD()[CU->getRawImportedEntities()].reset(nullptr);
     // If we ever start importing global variable defs, we'll need to
     // add their DIGlobalVariable to the globals list on the imported
     // DICompileUnit. Confirm none are imported, and then we can
@@ -1040,40 +1041,6 @@
                [](const GlobalValue *GV) { return isa<GlobalVariable>(GV); }) &&
            "Unexpected importing of a GlobalVariable definition");
     ValueMap.MD()[CU->getRawGlobalVariables()].reset(nullptr);
-
-    // Imported entities only need to be mapped in if they have local
-    // scope, as those might correspond to an imported entity inside a
-    // function being imported (any locally scoped imported entities that
-    // don't end up referenced by an imported function will not be emitted
-    // into the object). Imported entities not in a local scope
-    // (e.g. on the namespace) only need to be emitted by the originating
-    // module. Create a list of the locally scoped imported entities, and
-    // replace the source CUs imported entity list with the new list, so
-    // only those are mapped in.
-    // FIXME: Locally-scoped imported entities could be moved to the
-    // functions they are local to instead of listing them on the CU, and
-    // we would naturally only link in those needed by function importing.
-    SmallVector<TrackingMDNodeRef, 4> AllImportedModules;
-    bool ReplaceImportedEntities = false;
-    for (auto *IE : CU->getImportedEntities()) {
-      DIScope *Scope = IE->getScope();
-      assert(Scope && "Invalid Scope encoding!");
-      if (isa<DILocalScope>(Scope))
-        AllImportedModules.emplace_back(IE);
-      else
-        ReplaceImportedEntities = true;
-    }
-    if (ReplaceImportedEntities) {
-      if (!AllImportedModules.empty())
-        CU->replaceImportedEntities(MDTuple::get(
-            CU->getContext(),
-            SmallVector<Metadata *, 16>(AllImportedModules.begin(),
-                                        AllImportedModules.end())));
-      else
-        // If there were no local scope imported entities, we can map
-        // the whole list to nullptr.
-        ValueMap.MD()[CU->getRawImportedEntities()].reset(nullptr);
-    }
   }
 }
 
Index: test/ThinLTO/X86/debuginfo-cu-import.ll
===================================================================
--- test/ThinLTO/X86/debuginfo-cu-import.ll
+++ test/ThinLTO/X86/debuginfo-cu-import.ll
@@ -8,12 +8,13 @@
 ; Don't import enums, macros, retainedTypes or globals lists.
 ; Only import local scope imported entities.
 ; RUN: llvm-lto -thinlto-action=import %t2.bc -thinlto-index=%t.index.bc -o - | llvm-dis -o - | FileCheck %s
-; CHECK-NOT: DICompileUnit{{.*}} enums:
-; CHECK-NOT: DICompileUnit{{.*}} macros:
-; CHECK-NOT: DICompileUnit{{.*}} retainedTypes:
-; CHECK-NOT: DICompileUnit{{.*}} globals:
-; CHECK: DICompileUnit{{.*}} imports: ![[IMP:[0-9]+]]
-; CHECK: ![[IMP]] = !{!{{[0-9]+}}}
+; CHECK: DICompileUnit(
+; CHECK-NOT: enums:
+; CHECK-NOT: macros:
+; CHECK-NOT: retainedTypes:
+; CHECK-NOT: globals:
+; CHECK-NOT: imports:
+; CHECK-SAME: FullDebug){{$}}
 
 ; ModuleID = 'debuginfo-cu-import.c'
 source_filename = "debuginfo-cu-import.c"