[OpenMP][libomptarget] Suppress C++ 11 related warnings when building libomptarget-nvptx bitcode library, by Doru Bercea.

Summary: Pass -std=c++11 flag to compiler to suppress C++ 11 related warnings when building NVPTX bitcode library.

Reviewers: ABataev, caomhin, Hahnfeld

Reviewed By: ABataev, Hahnfeld

Subscribers: jdoerfert, Hahnfeld, jholewinski, mgorny, guansong, openmp-commits

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D55772

llvm-svn: 366438

Author: alexey-bataev

openmp/libomptarget/cmake/Modules/LibomptargetNVPTXBitcodeLibrary.cmake

@@ -78,7 +78,7 @@ endfunction()
 
 # These flags are required to emit LLVM Bitcode. We check them together because
 # if any of them are not supported, there is no point in finding out which are.
-set(compiler_flags_required -emit-llvm -O1 --cuda-device-only --cuda-path=${CUDA_TOOLKIT_ROOT_DIR})
+set(compiler_flags_required -emit-llvm -O1 --cuda-device-only -std=c++11 --cuda-path=${CUDA_TOOLKIT_ROOT_DIR})
 set(compiler_flags_required_src "extern \"C\" __device__ int thread() { return threadIdx.x; }")
 check_bitcode_compilation(LIBOMPTARGET_NVPTX_CUDA_COMPILER_SUPPORTS_FLAGS_REQUIRED "${compiler_flags_required_src}" ${compiler_flags_required})