Add regression test for recursive function using `return

Add a regression test that checks that recursive functions using a `return`
statement work correctly.

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

ivtest/ivltests/recursive_func2.v

@@ -0,0 +1,46 @@
+// Check that recursive functions are supported when the `return` statement is
+// used.
+
+module recursive_func();
+
+function automatic [15:0] factorial(input [15:0] n);
+  if (n > 1) begin : recursion
+    reg [15:0] result;
+    result = factorial(n - 1) * n;
+    return result;
+  end
+
+  return n;
+endfunction
+
+reg [15:0] r1;
+reg [15:0] r2;
+reg [15:0] r3;
+
+initial begin
+  fork
+    r1 = factorial(3);
+    r2 = factorial(4);
+    r3 = factorial(5);
+  join
+  $display("factorial 3 = %0d", r1);
+  $display("factorial 4 = %0d", r2);
+  $display("factorial 5 = %0d", r3);
+end
+
+wire [15:0] r4;
+wire [15:0] r5;
+wire [15:0] r6;
+
+assign r4 = factorial(6);
+assign r5 = factorial(7);
+assign r6 = factorial(8);
+
+initial begin
+  #1;
+  $display("factorial 6 = %0d", r4);
+  $display("factorial 7 = %0d", r5);
+  $display("factorial 8 = %0d", r6);
+end
+
+endmodule

ivtest/regress-sv.list

@@ -402,6 +402,7 @@ program5a		CE,-g2009		ivltests
 program5b		CE,-g2009		ivltests
 program_hello		normal,-g2009		ivltests
 program_hello2		CE,-g2009		ivltests
+recursive_func2		normal,-g2005-sv	ivltests gold=recursive_func.gold
 sbyte_test		normal,-g2005-sv	ivltests
 scalar_vector		normal,-g2005-sv	ivltests
 sf_countbits		normal,-g2012		ivltests

ivtest/regress-vlg.list

@@ -1469,7 +1469,7 @@ real_force_rel		normal			ivltests
 real_invalid_ops	CE			ivltests gold=real_invalid_ops.gold
 real_logical		normal			ivltests
 real_reg_force_rel	normal			ivltests
-recursive_func		normal			ivltests gold=recursive_func.gold
+recursive_func1		normal			ivltests gold=recursive_func.gold
 recursive_task		normal			ivltests gold=recursive_task.gold
 redef_net_error 	CE			ivltests
 redef_reg_error 	CE			ivltests

ivtest/regress-vlog95.list

@@ -90,7 +90,8 @@ pr2172606b		CE			ivltests
 pr2276163		CE			ivltests
 pr2929913		CE			ivltests
 real_events		CE			ivltests
-recursive_func		CE			ivltests
+recursive_func1		CE			ivltests
+recursive_func2		CE			ivltests
 recursive_task		CE			ivltests
 task_init_var1		CE,-pallowsigned=1	ivltests
 task_init_var2		CE,-pallowsigned=1	ivltests