convert for loop declarations and assignments to signle assignment (closes #15)

test/basic/for_decl.sv

@@ -0,0 +1,37 @@
+module top;
+
+    wire [0:31] a;
+    for (genvar n = 0; n < 32; n++) begin : gen_filter
+        assign a[n] = n & 1;
+    end
+
+    initial
+        for (integer i = 0; i < 32; i++)
+            $display("1: ", a[i]);
+
+    integer i = 0;
+    initial
+        for (; i < 32; i++)
+            $display("2: ", ~a[i]);
+
+    initial begin
+        for (integer i = 0, j = 42; i < 32; i++)
+            $display("3: ", ~a[i] + 5, " j=", j);
+    end
+
+    initial begin
+        integer i, j;
+        for (i = 0, j = 97; i < 32; i++)
+            $display("4: ", ~a[i] + 10, " j=", j);
+    end
+
+    integer j = 0, k;
+    initial begin
+        for (; j < 4; j++) begin
+            k = 0;
+            for (; k < 8; k++)
+                $display("5: ", ~a[j * 8 + k] + 11);
+        end
+    end
+
+endmodule

test/basic/for_decl.v

@@ -0,0 +1,45 @@
+module top;
+
+    wire [0:31] a;
+    generate
+        genvar n;
+        for (n = 0; n < 32; n = n + 1) begin : gen_filter
+            assign a[n] = n & 1;
+        end
+    endgenerate
+
+    integer i;
+    initial begin : foo_1
+        for (i = 0; i < 32; i = i + 1)
+            $display("1: ", a[i]);
+    end
+
+    initial begin : foo_2
+        integer i;
+        for (i = 0; i < 32; i = i + 1)
+            $display("2: ", ~a[i]);
+    end
+
+    initial begin : foo_3
+        integer i;
+        integer j;
+        j = 42;
+        for (i = 0; i < 32; i = i + 1)
+            $display("3: ", ~a[i] + 5, " j=", j);
+    end
+
+    initial begin : foo_4
+        integer i, j;
+        j = 97;
+        for (i = 0; i < 32; i = i + 1)
+            $display("4: ", ~a[i] + 10, " j=", j);
+    end
+
+    integer j, k;
+    initial begin
+        for (j = 0; j < 4; j++)
+            for (k = 0; k < 8; k++)
+                $display("5: ", ~a[j * 8 + k] + 11);
+    end
+
+endmodule