[amdgpu][nfc] Fix build with a certan Clang version

[gribozavr]

Summary

It errors out in the Bazel CI:

AMDGPULowerModuleLDSPass.cpp:384:12: error: chosen constructor is
explicit in copy-initialization

return {SGV, std::move(Map)};

llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp

for (size_t I = 0; I < LocalVars.size(); I++) {
       if (IsPaddingField[I]) {
         assert(GV->use_empty());
         GV->eraseFromParent();
       } else {
         Map[GV] = GEP;
       }
     }
     assert(Map.size() == LDSVarsToTransform.size());
-    return {SGV, std::move(Map)};
+    return std::make_tuple(SGV, std::move(Map));
   }
 
   template <typename PredicateTy>
   void replaceLDSVariablesWithStruct(
       Module &M, std::vector<GlobalVariable *> const &LDSVarsToTransform,
       GlobalVariable *SGV,
       DenseMap<GlobalVariable *, Constant *> &LDSVarsToConstantGEP,
       PredicateTy Predicate) {