pack arrays assigned to other arrays

test/basic/array.sv

@@ -0,0 +1,5 @@
+module top;
+    logic [1:0] a [3];
+    logic [1:0] b [3];
+    always_comb a = b;
+endmodule

test/basic/array.v

@@ -0,0 +1,5 @@
+module top;
+    reg [5:0] a;
+    wire [5:0] b;
+    always @(*) a = b;
+endmodule