[libgomp/testsuite] Fix libgomp.fortran/examples-4/declare_target-{1,2}.f90

The test-cases libgomp.fortran/examples-4/declare_target-{1,2}.f90 mean to
set an nvptx-specific limit using offload_target_nvptx, but also change
behaviour for amd.

That is, there is now a difference in behaviour between:
- a compiler configured for GCN offloading, and
- a compiler configured for both GCN and nvptx offloading.

Fix this by using instead on_device_arch_nvptx.

Tested on x86_64 with nvptx accelerator.

libgomp/ChangeLog:

2022-04-04  Tom de Vries  <tdevries@suse.de>

	* testsuite/libgomp.fortran/examples-4/on_device_arch.c: Copy from
	parent dir.
	* testsuite/libgomp.fortran/examples-4/declare_target-1.f90: Use
	on_device_arch_nvptx instead of offload_target_nvptx.
	* testsuite/libgomp.fortran/examples-4/declare_target-2.f90: Same.

---
 .../examples-4/declare_target-1.f90                | 31 +++++++++++++---------
 .../examples-4/declare_target-2.f90                | 31 +++++++++++++---------
 .../libgomp.fortran/examples-4/on_device_arch.c    |  3 +++
 3 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-1.f90 b/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-1.f90
index 03c5c53ed67..acded20f756 100644
--- a/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-1.f90
+++ b/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-1.f90
@@ -1,16 +1,6 @@
 ! { dg-do run }
-! { dg-additional-options "-cpp" }
-! Reduced from 25 to 23, otherwise execution runs out of thread stack on
-! Nvidia Titan V.
-! Reduced from 23 to 22, otherwise execution runs out of thread stack on
-! Nvidia T400 (2GB variant), when run with GOMP_NVPTX_JIT=-O0.
-! Reduced from 22 to 20, otherwise execution runs out of thread stack on
-! Nvidia RTX A2000 (6GB variant), when run with GOMP_NVPTX_JIT=-O0.
-! { dg-additional-options "-DREC_DEPTH=20" { target { offload_target_nvptx } } } */
-
-#ifndef REC_DEPTH
-#define REC_DEPTH 25
-#endif
+! { dg-additional-sources on_device_arch.c }
+! { dg-prune-output "command-line option '-fintrinsic-modules-path=.*' is valid for Fortran but not for C" }
 
 module e_53_1_mod
   integer :: THRESHOLD = 20
@@ -38,6 +28,23 @@ end module
 
 program e_53_1
   use e_53_1_mod, only : fib, fib_wrapper
+  integer :: REC_DEPTH = 25
+
+  interface
+    integer function on_device_arch_nvptx() bind(C)
+    end function on_device_arch_nvptx
+  end interface
+
+  if (on_device_arch_nvptx () /= 0) then
+     ! Reduced from 25 to 23, otherwise execution runs out of thread stack on
+     ! Nvidia Titan V.
+     ! Reduced from 23 to 22, otherwise execution runs out of thread stack on
+     ! Nvidia T400 (2GB variant), when run with GOMP_NVPTX_JIT=-O0.
+     ! Reduced from 22 to 20, otherwise execution runs out of thread stack on
+     ! Nvidia RTX A2000 (6GB variant), when run with GOMP_NVPTX_JIT=-O0.
+     REC_DEPTH = 20
+  end if
+
   if (fib (15) /= fib_wrapper (15)) stop 1
   if (fib (REC_DEPTH) /= fib_wrapper (REC_DEPTH)) stop 2
 end program
diff --git a/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-2.f90 b/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-2.f90
index 0e8bea578a8..27a5cec2e9d 100644
--- a/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-2.f90
+++ b/libgomp/testsuite/libgomp.fortran/examples-4/declare_target-2.f90
@@ -1,20 +1,27 @@
 ! { dg-do run }
-! { dg-additional-options "-cpp" }
-! Reduced from 25 to 23, otherwise execution runs out of thread stack on
-! Nvidia Titan V.
-! Reduced from 23 to 22, otherwise execution runs out of thread stack on
-! Nvidia T400 (2GB variant), when run with GOMP_NVPTX_JIT=-O0.
-! Reduced from 22 to 18, otherwise execution runs out of thread stack on
-! Nvidia RTX A2000 (6GB variant), when run with GOMP_NVPTX_JIT=-O0.
-! { dg-additional-options "-DREC_DEPTH=18" { target { offload_target_nvptx } } } */
-
-#ifndef REC_DEPTH
-#define REC_DEPTH 25
-#endif
+! { dg-additional-sources on_device_arch.c }
+! { dg-prune-output "command-line option '-fintrinsic-modules-path=.*' is valid for Fortran but not for C" }
 
 program e_53_2
   !$omp declare target (fib)
   integer :: x, fib
+  integer :: REC_DEPTH = 25
+
+  interface
+    integer function on_device_arch_nvptx() bind(C)
+    end function on_device_arch_nvptx
+  end interface
+
+  if (on_device_arch_nvptx () /= 0) then
+     ! Reduced from 25 to 23, otherwise execution runs out of thread stack on
+     ! Nvidia Titan V.
+     ! Reduced from 23 to 22, otherwise execution runs out of thread stack on
+     ! Nvidia T400 (2GB variant), when run with GOMP_NVPTX_JIT=-O0.
+     ! Reduced from 22 to 18, otherwise execution runs out of thread stack on
+     ! Nvidia RTX A2000 (6GB variant), when run with GOMP_NVPTX_JIT=-O0.
+     REC_DEPTH = 18
+  end if
+
   !$omp target map(from: x)
     x = fib (REC_DEPTH)
   !$omp end target
diff --git a/libgomp/testsuite/libgomp.fortran/examples-4/on_device_arch.c b/libgomp/testsuite/libgomp.fortran/examples-4/on_device_arch.c
new file mode 100644
index 00000000000..f8bef19e021
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/examples-4/on_device_arch.c
@@ -0,0 +1,3 @@
+/* Auxiliar file.  */
+/* { dg-do compile  { target skip-all-targets } } */
+#include "../../libgomp.c-c++-common/on_device_arch.h"