Ensure gcc-16 compatibility.

Fix is_present for descriptor arrays in gcc-16.
Remove compiling warning from test_case.

Author: vehre

src/runtime-libraries/mpi/mpi_caf.c

@@ -6095,19 +6095,19 @@ PREFIX(is_present_on_remote)(caf_token_t token, const int image_index,
 
   if (this_image == remote_image)
   {
+    mpi_caf_token_t *mpi_token = (mpi_caf_token_t *)token;
     int32_t result = 0;
     mpi_caf_token_t src_token = {get_data, MPI_WIN_NULL, NULL};
-    void *src_ptr = ((mpi_caf_token_t *)token)->memptr;
-
-    dprint("Shortcutting due to self access on image %d.\n", image_index);
-    accessor_hash_table[is_present_index].u.is_present(add_data, &this_image,
-                                                       &result,
 #ifdef GCC_GE_16
-                                                       &src_ptr,
+    void *src_ptr
+        = mpi_token->desc ? mpi_token->desc : (void *)&mpi_token->memptr;
 #else
-                                                       src_ptr,
+    void *src_ptr = mpi_token->memptr;
 #endif
-                                                       &src_token, 0);
+
+    dprint("Shortcutting due to self access on image %d.\n", image_index);
+    accessor_hash_table[is_present_index].u.is_present(
+        add_data, &this_image, &result, src_ptr, &src_token, 0);
 
     return result;
   }

src/tests/unit/collectives/co_reduce_string.f90

@@ -40,7 +40,7 @@ program co_reduce_strings
   associate (me => this_image())
     allocate(strarr(numstrings)[*])
     do i = 1, numstrings
-      write(strarr(i), "('foo'I02)") i * me
+      write(strarr(i), "('foo',I02)") i * me
     end do
     ! Collectively reduce the maximum string.
     call co_reduce(strarr, strmax)
@@ -50,7 +50,7 @@ program co_reduce_strings
   ! implicitly synchronizes.
   associate (np => num_images())
     do i = 1, np
-      write (expect, "('foo'I02)") i * np
+      write (expect, "('foo',I02)") i * np
       if (strarr(i) /= expect) then
         ! On errror print what we got and what we expected.
         print *, "Got: ", strarr(i), ", expected: ", expect
@@ -77,4 +77,3 @@ pure function strmax(lhs, rhs) result(maxstr) bind(C,name="strmax")
   end function
 
 end program co_reduce_strings
-