Add regression test for inherited non-void function calls

Check that a bare inherited non-void function call used as a statement emits
the required discarded-return warning and executes the function.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

ivtest/gold/sv_class_method_call_nonvoid-iverilog-stderr.gold

@@ -0,0 +1 @@
+ivltests/sv_class_method_call_nonvoid.v:14: warning: User function 'value' is being called as a task.

ivtest/gold/sv_class_method_call_nonvoid-vvp-stdout.gold

@@ -0,0 +1 @@
+PASSED

ivtest/ivltests/sv_class_method_call_nonvoid.v

@@ -0,0 +1,32 @@
+// Check that a bare inherited non-void function can be called as a statement.
+
+class B;
+  int calls;
+
+  function int value();
+    calls = calls + 1;
+    return calls;
+  endfunction
+endclass
+
+class C extends B;
+  function void run();
+    value();
+  endfunction
+endclass
+
+module test;
+  C object;
+
+  initial begin
+    object = new;
+    object.calls = 0;
+    object.run();
+
+    if (object.calls !== 1) begin
+      $display("FAILED: expected one call, got %0d", object.calls);
+    end else begin
+      $display("PASSED");
+    end
+  end
+endmodule

ivtest/regress-vvp.list

@@ -290,6 +290,7 @@ sv_class_const_nested_block	vvp_tests/sv_class_const_nested_block.json
 sv_class_const_static_assign_fail vvp_tests/sv_class_const_static_assign_fail.json
 sv_class_const_static_init	vvp_tests/sv_class_const_static_init.json
 sv_class_const_static_local_fail vvp_tests/sv_class_const_static_local_fail.json
+sv_class_method_call_nonvoid	vvp_tests/sv_class_method_call_nonvoid.json
 sv_class_nested_method_call	vvp_tests/sv_class_nested_method_call.json
 sv_class_prop_assign_op1	vvp_tests/sv_class_prop_assign_op1.json
 sv_class_prop_assign_op2	vvp_tests/sv_class_prop_assign_op2.json

ivtest/vvp_tests/sv_class_method_call_nonvoid.json

@@ -0,0 +1,11 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_class_method_call_nonvoid.v",
+    "iverilog-args" : [ "-g2005-sv" ],
+    "gold"          : "sv_class_method_call_nonvoid",
+    "vlog95" : {
+        "__comment" : "Classes are not supported",
+        "type"      : "CE",
+        "gold"      : ""
+    }
+}