Add regression tests for tasks and void function calls in expression

Check that an error is reported when either calling a task or a void
function as part of an expression.

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

ivtest/ivltests/func_void_in_expr_fail.v

@@ -0,0 +1,14 @@
+// Check that an error is reported when a void function is used in an expression
+
+module test;
+
+  function void f;
+  endfunction
+
+  initial begin
+    int x;
+    x = f() + 1; // This should fail, void function can not be used in expression
+    $display("FAILED");
+  end
+
+endmodule

ivtest/ivltests/task_in_expr_fail.v

@@ -0,0 +1,14 @@
+// Check that an error is reported when a task is used in an expression
+
+module test;
+
+  task t;
+  endtask
+
+  initial begin
+    int x;
+    x = t() + 1; // This should fail, task can not be used in expression
+    $display("FAILED");
+  end
+
+endmodule

ivtest/regress-sv.list

@@ -312,6 +312,7 @@ fr49			normal,-g2009		ivltests
 func_init_var1		normal,-g2009		ivltests
 func_init_var2		normal,-g2009		ivltests
 func_init_var3		normal,-g2009		ivltests
+func_void_in_expr_fail	CE,-g2005-sv		ivltests
 function10		CO,-g2005-sv		ivltests
 function11		CE,-g2005-sv		ivltests
 function12		normal,-g2005-sv	ivltests gold=function12.gold

ivtest/regress-vlg.list

@@ -1650,6 +1650,7 @@ task3.14D		normal			ivltests
 task3.14E		normal			ivltests
 task3.14F		normal			ivltests
 task_bypath		normal			ivltests # task enabled by complete path name.
+task_in_expr_fail	CE			ivltests
 task_inpad		normal			ivltests # Validates input of task should pad w/ 0
 task_iotypes		normal			ivltests # task ports with types.
 task_iotypes2		normal			ivltests # task ports with types.