Revert "Remove redundant "std::move"s in return statements"

The build failed with

  error: call to deleted constructor of 'llvm::Error'

errors.

This reverts commit 1c2241a7936bf85aa68aef94bd40c3ba77d8ddf2.
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index 404c438..2df71a5 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -194,7 +194,7 @@
                                          CodeSize, CodeAlign,
                                          RODataSize, RODataAlign,
                                          RWDataSize, RWDataAlign))
-      return Err;
+      return std::move(Err);
     MemMgr.reserveAllocationSpace(CodeSize, CodeAlign, RODataSize, RODataAlign,
                                   RWDataSize, RWDataAlign);
   }
@@ -319,7 +319,7 @@
       // Get symbol offset.
       uint64_t SectOffset;
       if (auto Err = getOffset(*I, *SI, SectOffset))
-        return Err;
+        return std::move(Err);
 
       bool IsCode = SI->isText();
       unsigned SectionID;
@@ -341,7 +341,7 @@
   // Allocate common symbols
   if (auto Err = emitCommonSymbols(Obj, CommonSymbolsToAllocate, CommonSize,
                                    CommonAlign))
-    return Err;
+    return std::move(Err);
 
   // Parse and process relocations
   LLVM_DEBUG(dbgs() << "Parse relocations:\n");
@@ -432,7 +432,7 @@
 
   // Give the subclasses a chance to tie-up any loose ends.
   if (auto Err = finalizeLoad(Obj, LocalSections))
-    return Err;
+    return std::move(Err);
 
 //   for (auto E : LocalSections)
 //     llvm::dbgs() << "Added: " << E.first.getRawDataRefImpl() << " -> " << E.second << "\n";