Pass a && to getLazyBitcodeModule.

This forces callers to use std::move when calling it. It is somewhat odd to have
code with std::move that doesn't always move, but it is also odd to have code
without std::move that sometimes moves.

llvm-svn: 217049

llvm/unittests/Bitcode/BitReaderTest.cpp

@@ -53,7 +53,8 @@ static std::unique_ptr<Module> getLazyModuleFromAssembly(LLVMContext &Context,
   writeModuleToBuffer(parseAssembly(Assembly), Mem);
   std::unique_ptr<MemoryBuffer> Buffer =
       MemoryBuffer::getMemBuffer(Mem.str(), "test", false);
-  ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModule(Buffer, Context);
+  ErrorOr<Module *> ModuleOrErr =
+      getLazyBitcodeModule(std::move(Buffer), Context);
   return std::unique_ptr<Module>(ModuleOrErr.get());
 }