Add additional regression tests for issue steveicarus#1099.

ivtest/ivltests/br_gh1099b.v

@@ -0,0 +1,24 @@
+module top;
+    reg [3:0] inp1;
+    reg signed [3:0] inp2;
+    wire [4:0] out1, out2;
+    initial begin
+        $monitor("%b %b %b %b", inp1, inp2, out1, out2);
+        #1 inp1 = 4'b1111;
+        #1 inp2 = 4'b1111;
+        #1;
+        if ((out1 === 5'b01111) && (out2 === 5'b01111))
+            $display("PASSED");
+        else
+            $display("FAILED");
+    end
+    mod m1(inp1[3:0], out1);
+    mod m2(inp2[3:0], out2);
+endmodule
+
+module mod(
+    input [4:0] inp,
+    output [4:0] out
+);
+    assign out = inp;
+endmodule

ivtest/ivltests/br_gh1099c.v

@@ -0,0 +1,24 @@
+module top;
+    reg [3:0] inp1;
+    reg signed [3:0] inp2;
+    wire [4:0] out1, out2;
+    initial begin
+        $monitor("%b %b %b %b", inp1, inp2, out1, out2);
+        #1 inp1 = 4'b1111;
+        #1 inp2 = 4'b1111;
+        #1;
+        if ((out1 === 5'b01111) && (out2 === 5'b01111))
+            $display("PASSED");
+        else
+            $display("FAILED");
+    end
+    mod m1($unsigned(inp1), out1);
+    mod m2($unsigned(inp2), out2);
+endmodule
+
+module mod(
+    input [4:0] inp,
+    output [4:0] out
+);
+    assign out = inp;
+endmodule

ivtest/regress-vvp.list

@@ -42,7 +42,9 @@ br_gh1087a2			vvp_tests/br_gh1087a2.json
 br_gh1087a3			vvp_tests/br_gh1087a3.json
 br_gh1087b			vvp_tests/br_gh1087b.json
 br_gh1087c			vvp_tests/br_gh1087c.json
-br_gh1099			vvp_tests/br_gh1099.json
+br_gh1099a			vvp_tests/br_gh1099a.json
+br_gh1099b			vvp_tests/br_gh1099b.json
+br_gh1099c			vvp_tests/br_gh1099c.json
 br_gh1104			vvp_tests/br_gh1104.json
 ca_time_real`			vvp_tests/ca_time_real.json
 case1				vvp_tests/case1.json

ivtest/vvp_tests/br_gh1099a.json

@@ -0,0 +1,4 @@
+{
+    "type"   : "normal",
+    "source" : "br_gh1099a.v"
+}

ivtest/vvp_tests/br_gh1099b.json

@@ -0,0 +1,4 @@
+{
+    "type"   : "normal",
+    "source" : "br_gh1099b.v"
+}

ivtest/vvp_tests/br_gh1099c.json

@@ -0,0 +1,4 @@
+{
+    "type"   : "normal",
+    "source" : "br_gh1099c.v"
+}