[OpenMP][iwyu] explicitly includes `<algorithm>` in CUDA rtl.cpp

[cjdb]

Summary

Compiling with Clang modules and libc++ identified that rtl.cpp is using
std::fill without first including <algorithm>.

[JonChesterfield]

openmp/libomptarget/plugins/cuda/src/rtl.cpp

199

std::fill use here, looks like we could memset to avoid including algorithm

[jhuber6]

openmp/libomptarget/plugins/cuda/src/rtl.cpp

199

Is it worth avoiding it altogether? It's already included in the AMDGPU plugin, but it doesn't seem to be used for anything there.

[jdoerfert]

LG, thanks for the contribution

[cjdb]

rebases to activate CI: will merge as soon as it's green

openmp/libomptarget/plugins/cuda/src/rtl.cpp

 //===----RTLs/cuda/src/rtl.cpp - Target RTLs Implementation ------- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // RTL for CUDA machine
 //
 //===----------------------------------------------------------------------===//
 
+#include <algorithm>
 #include <cassert>
 #include <cstddef>
 #include <cuda.h>
 #include <list>
 #include <memory>
 #include <mutex>
 #include <string>
 #include <unordered_map>
 #include <vector>
 
 #include "Debug.h"
StreamManagerTy(const int NumberOfDevices,
     StreamPool.resize(NumberOfDevices);
     NextStreamId.resize(NumberOfDevices);
     StreamMtx.resize(NumberOfDevices);
 
     if (const char *EnvStr = getenv("LIBOMPTARGET_NUM_INITIAL_STREAMS"))
       EnvNumInitialStreams = std::stoi(EnvStr);
 
     // Initialize the next stream id
     std::fill(NextStreamId.begin(), NextStreamId.end(), 0);
 
     // Initialize stream mutex
     for (std::unique_ptr<std::mutex> &Ptr : StreamMtx)
       Ptr = std::make_unique<std::mutex>();
   }
 
   ~StreamManagerTy() {
     // Destroy streams