[nvptx] Verify dimension limits after applying defaults

There's a problem in oacc_validate_dims that when f.i. the worker dimension
is set using -fopenacc-dim=:32, and the vector_length is set using a
"vector_length (128)" clause, the compiler combines, accepts and emits the
values, while the combination of the two is invalid.

The reason for this is that while oacc_validate_dims validates the dimensions
using targetm.goacc.validate_dims before applying default or minimum values,
it does not do so afterwards.

Work around this in the nvptx port by applying the defaults from
oacc_default_dims at the end of nvptx_goacc_validate_dims_1, as
oacc_validate_dims would do it, and then apply the dimensions limits.

2019-01-12  Tom de Vries  <tdevries@suse.de>

	PR middle-end/88703
	* config/nvptx/nvptx.c (nvptx_goacc_validate_dims_1): Apply defaults
	from oacc_default_dims, as oacc_validate_dims would do it, and apply
	dimensions limits.

From-SVN: r267877

gcc/ChangeLog

 2019-01-12  Tom de Vries  <tdevries@suse.de>
 
+	PR middle-end/88703
+	* config/nvptx/nvptx.c (nvptx_goacc_validate_dims_1): Apply defaults
+	from oacc_default_dims, as oacc_validate_dims would do it, and apply
+	dimensions limits.
+
+2019-01-12  Tom de Vries  <tdevries@suse.de>
+
 	* config/nvptx/nvptx.c (nvptx_goacc_validate_dims_1)
 	(nvptx_goacc_validate_dims): Add used parameter.
 	* doc/tm.texi: Regenerate.

gcc/config/nvptx/nvptx.c

@@ -5703,6 +5703,23 @@ nvptx_goacc_validate_dims_1 (tree decl, int dims[], int fn_level, unsigned used)
 	dims[GOMP_DIM_GANG] = PTX_DEFAULT_RUNTIME_DIM;
       nvptx_apply_dim_limits (dims);
     }
+
+  if (offload_region_p)
+    {
+      for (i = 0; i < GOMP_DIM_MAX; i++)
+	{
+	  if (!(dims[i] < 0))
+	    continue;
+
+	  if ((used & GOMP_DIM_MASK (i)) == 0)
+	    /* Function oacc_validate_dims will apply the minimal dimension.  */
+	    continue;
+
+	  dims[i] = oacc_get_default_dim (i);
+	}
+
+      nvptx_apply_dim_limits (dims);
+    }
 }
 
 /* Validate compute dimensions of an OpenACC offload or routine, fill