Add soa_zip and soa_unzip to demo.odin

examples/demo/demo.odin

@@ -1760,8 +1760,6 @@ range_statements_with_multiple_return_values :: proc() {
 
 
 soa_struct_layout :: proc() {
-	// IMPORTANT NOTE(bill, 2019-11-03): This feature is subject to be changed/removed
-	// NOTE(bill): Most likely #soa [N]T
 	fmt.println("\n#SOA Struct Layout");
 
 	{
@@ -1858,6 +1856,30 @@ soa_struct_layout :: proc() {
 		fmt.println(cap(d));
 		fmt.println(d[:]);
 	}
+	{ // soa_zip and soa_unzip
+		fmt.println("\nsoa_zip and soa_unzip");
+
+		x := []i32{1, 3, 9};
+		y := []f32{2, 4, 16};
+		z := []b32{true, false, true};
+
+		// produce an #soa slice the normal slices passed
+		s := soa_zip(a=x, b=y, c=z);
+
+		// iterate over the #soa slice
+		for v, i in s {
+			fmt.println(v); // exactly the same as s[i]
+			// NOTE: 'v' is NOT a temporary value but has a specialized addressing mode
+			// which means that when accessing v.a etc, it does the correct transformation
+			// internally:
+			//         s[i].a === s.a[i]
+			fmt.println(v.a, v.b, v.c);
+		}
+
+		// Recover the slices from the #soa slice
+		a, b, c := soa_unzip(s);
+		fmt.println(a, b, c);
+	}
 }
 
 constant_literal_expressions :: proc() {