address type lookup of $unsigned and $signed

src/Convert/TypeOf.hs

@@ -81,6 +81,10 @@ typeof (Number n) =
         r = (RawNum $ size - 1, RawNum 0)
         size = numberBitLength n
         sg = if numberIsSigned n then Signed else Unspecified
+typeof (Call (Ident "$unsigned") (Args [e] [])) =
+    typeof e
+typeof (Call (Ident "$signed") (Args [e] [])) =
+    typeof e
 typeof (Call (Ident x) _) =
     typeof $ Ident x
 typeof (orig @ (Bit e _)) = do

test/basic/unbased_unsized.sv

@@ -112,6 +112,20 @@ module top;
         arr = '{default: 'x}; $display("%b", arr);
         arr = '{default: 'z}; $display("%b", arr);
     end
+
+    reg pick;
+    logic [8:0] w0, w1, w2, w3;
+    assign w0 = pick ? '1 : $unsigned(4'd0);
+    assign w1 = pick ? '1 : unsigned'(5'd0);
+    assign w2 = pick ? '1 : $signed(6'd0);
+    assign w3 = pick ? '1 : signed'(7'd0);
+    initial begin
+        $monitor("%0d %b %b %b %b %b", $time, pick, w0, w1, w2, w3);
+        #1 pick = 0;
+        #1 pick = 1;
+        #1 pick = 0;
+        #1 pick = 1;
+    end
 endmodule
 
 module M(a, b, c, d);

test/basic/unbased_unsized.v

@@ -107,6 +107,20 @@ module top;
         arr = 1'sbx; $display("%b", arr);
         arr = 1'sbz; $display("%b", arr);
     end
+
+    reg pick;
+    wire [8:0] w0, w1, w2, w3;
+    assign w0 = pick ? 9'h1FF : 9'h000;
+    assign w1 = pick ? 9'h1FF : 9'h000;
+    assign w2 = pick ? 9'h1FF : 9'h000;
+    assign w3 = pick ? 9'h1FF : 9'h000;
+    initial begin
+        $monitor("%0d %b %b %b %b %b", $time, pick, w0, w1, w2, w3);
+        #1 pick = 0;
+        #1 pick = 1;
+        #1 pick = 0;
+        #1 pick = 1;
+    end
 endmodule
 
 module M(a, b, c, d);