cmake: Update CUDA C++11 build flags

nvcc can't use only -Xcompiler -std=c++11, it needs -std=c++11 in the whole
pipeline.

The real fix is in CMake 3.3.

Kitware/CMake@99abebd

Fix #818.

Author: xlz

CMakeLists.txt

@@ -344,21 +344,24 @@ IF(ENABLE_CUDA)
     SET(LIBFREENECT2_WITH_CUDA_SUPPORT 1)
     SET(HAVE_CUDA yes)
 
-    STRING(REPLACE "\\" "/" NVCUDASAMPLES_ROOT "$ENV{NVCUDASAMPLES_ROOT};$ENV{NVCUDASAMPLES8_0_ROOT}")
+    STRING(REPLACE "\\" "/" NVCUDASAMPLES_ROOT "$ENV{NVCUDASAMPLES_ROOT}")
+    STRING(REPLACE "\\" "/" NVCUDASAMPLES8_0_ROOT "$ENV{NVCUDASAMPLES8_0_ROOT}")
     CUDA_INCLUDE_DIRECTORIES(
       "${MY_DIR}/include/"
       "${CUDA_TOOLKIT_ROOT_DIR}/samples/common/inc"
       "${NVCUDASAMPLES_ROOT}/common/inc"
+      "${NVCUDASAMPLES8_0_ROOT}/common/inc"
     )
     SET(CUDA_FLAGS -use_fast_math)
     IF(NOT MSVC)
       SET(CUDA_FLAGS "${CUDA_FLAGS} -Xcompiler -fPIC")
     ENDIF()
+    IF(HAVE_CXX11 EQUAL yes AND CUDA_VERSION VERSION_GREATER 7.0)
+      SET(CUDA_FLAGS "${CUDA_FLAGS} -std=c++11")
+    ENDIF()
 
     SET(OLD_CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-    IF(CUDA_VERSION VERSION_LESS 7.0)
-      STRING(REGEX REPLACE "-std=c\\+\\+.." "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-    ENDIF()
+    STRING(REGEX REPLACE "-std=c\\+\\+.." "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
     CUDA_COMPILE(CUDA_OBJECTS
       src/cuda_depth_packet_processor.cu
       src/cuda_kde_depth_packet_processor.cu