Move 'libgomp/plugin/cuda/cuda.h' to 'include/cuda/cuda.h'

... so that it may be used by other projects that inherit GCC's 'include'
directory.

	include/
	* cuda/cuda.h: New file.
	libgomp/
	* plugin/cuda/cuda.h: Remove file.
	* plugin/plugin-nvptx.c [PLUGIN_NVPTX_DYNAMIC]: Include
	"cuda/cuda.h" instead of <cuda.h>.
	* plugin/configfrag.ac <PLUGIN_NVPTX_DYNAMIC>: Don't set
	'PLUGIN_NVPTX_CPPFLAGS'.
	* configure: Regenerate.

include/cuda/cuda.h

@@ -1,4 +1,4 @@
-/* CUDA API description.
+/* CUDA Driver API description.
    Copyright (C) 2017-2022 Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -22,9 +22,8 @@ a copy of the GCC Runtime Library Exception along with this program;
 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 <http://www.gnu.org/licenses/>.
 
-This header provides the minimum amount of typedefs, enums and function
-declarations to be able to compile plugin-nvptx.c if cuda.h and
-libcuda.so.1 are not available.  */
+This header provides parts of the CUDA Driver API, without having to rely on
+the proprietary CUDA toolkit.  */
 
 #ifndef GCC_CUDA_H
 #define GCC_CUDA_H

libgomp/configure

@@ -15362,7 +15362,6 @@ rm -f core conftest.err conftest.$ac_objext \
 		       && (test "x$CUDA_DRIVER_LIB" = x \
 			   || test "x$CUDA_DRIVER_LIB" = xno); then
 		      PLUGIN_NVPTX=1
-		      PLUGIN_NVPTX_CPPFLAGS='-I$(srcdir)/plugin/cuda'
 		      PLUGIN_NVPTX_LIBS='-ldl'
 		      PLUGIN_NVPTX_DYNAMIC=1
 		    else

libgomp/plugin/configfrag.ac

@@ -197,7 +197,6 @@ if test x"$enable_offload_targets" != x; then
 		       && (test "x$CUDA_DRIVER_LIB" = x \
 			   || test "x$CUDA_DRIVER_LIB" = xno); then
 		      PLUGIN_NVPTX=1
-		      PLUGIN_NVPTX_CPPFLAGS='-I$(srcdir)/plugin/cuda'
 		      PLUGIN_NVPTX_LIBS='-ldl'
 		      PLUGIN_NVPTX_DYNAMIC=1
 		    else

libgomp/plugin/plugin-nvptx.c

@@ -41,7 +41,11 @@
 #include "oacc-int.h"
 
 #include <pthread.h>
-#include <cuda.h>
+#if PLUGIN_NVPTX_DYNAMIC
+# include "cuda/cuda.h"
+#else
+# include <cuda.h>
+#endif
 #include <stdbool.h>
 #include <limits.h>
 #include <string.h>