Add regression test for invalid named function return type

Check that an unresolved named function return type is diagnosed during
elaboration rather than being rejected while parsing.

Signed-off-by: Lars-Peter Clausen <[email protected]>

ivtest/gold/sv_function_named_return_type_fail-iverilog-stderr.gold

@@ -0,0 +1,2 @@
+ivltests/sv_function_named_return_type_fail.v:5: error: `missing_type` is not a type.
+1 error(s) during elaboration.

ivtest/ivltests/sv_function_named_return_type_fail.v

@@ -0,0 +1,9 @@
+// Check that an undefined named function return type fails during elaboration.
+
+module test;
+
+  function missing_type f;
+    f = 0;
+  endfunction
+
+endmodule

ivtest/regress-vvp.list

@@ -377,6 +377,7 @@ sv_function_call_chain_unit_precedence	vvp_tests/sv_function_call_chain_unit_pre
 sv_function_call_receiver_unit_order	vvp_tests/sv_function_call_receiver_unit_order.json
 sv_function_call_unit_import_precedence	vvp_tests/sv_function_call_unit_import_precedence.json
 sv_function_call_unit_precedence	vvp_tests/sv_function_call_unit_precedence.json
+sv_function_named_return_type_fail	vvp_tests/sv_function_named_return_type_fail.json
 sv_function_statement_order_event_fail	vvp_tests/sv_function_statement_order_event_fail.json
 sv_function_statement_order_parameter_fail	vvp_tests/sv_function_statement_order_parameter_fail.json
 sv_function_statement_order_variable_fail	vvp_tests/sv_function_statement_order_variable_fail.json

ivtest/vvp_tests/sv_function_named_return_type_fail.json

@@ -0,0 +1,6 @@
+{
+    "type"          : "CE",
+    "source"        : "sv_function_named_return_type_fail.v",
+    "gold"          : "sv_function_named_return_type_fail",
+    "iverilog-args" : [ "-g2005-sv" ]
+}