Add regression tests for specparam reference order

Check separately that a module-body specparam declaration following a
reference is rejected and that a specparam declared in a specify block
remains visible before its declaration.

Run both tests through the native and vlog95 backends.

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

ivtest/ivltests/specparam_reference_order_fail.v

@@ -0,0 +1,9 @@
+// Check that a module-body specparam is declared before it is referenced.
+
+module test;
+
+  wire value;
+  assign value = delay;
+  specparam delay = 1;
+
+endmodule

ivtest/ivltests/specparam_specify_reference_order.v

@@ -0,0 +1,18 @@
+// Check that specify-block specparams can be referenced before declaration.
+
+module test;
+
+  specify
+    specparam value = delay;
+    specparam delay = 42;
+  endspecify
+
+  initial begin
+    if (value !== 42) begin
+      $display("FAILED. Expected 42, got %0d", value);
+    end else begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/regress-vvp.list

@@ -234,6 +234,8 @@ sf_onehot_fail			vvp_tests/sf_onehot_fail.json
 sf_onehot0_fail			vvp_tests/sf_onehot0_fail.json
 shift6				vvp_tests/shift6.json
 single_element_array		vvp_tests/single_element_array.json
+specparam_reference_order_fail	vvp_tests/specparam_reference_order_fail.json
+specparam_specify_reference_order	vvp_tests/specparam_specify_reference_order.json
 struct_enum_partsel		vvp_tests/struct_enum_partsel.json
 struct_field_left_right		vvp_tests/struct_field_left_right.json
 struct_nested1			vvp_tests/struct_nested1.json

ivtest/vvp_tests/specparam_reference_order_fail.json

@@ -0,0 +1,5 @@
+{
+    "type"          : "CE",
+    "source"        : "specparam_reference_order_fail.v",
+    "iverilog-args" : [ "-g2001" ]
+}

ivtest/vvp_tests/specparam_specify_reference_order.json

@@ -0,0 +1,4 @@
+{
+    "type"   : "normal",
+    "source" : "specparam_specify_reference_order.v"
+}