Add more Zig test programs.

tests/hellozig/while.zig

@@ -0,0 +1,38 @@
+const std = @import("std");
+const print = std.debug.print;
+
+pub fn main() !void {
+    var a: usize = 0;
+    var b: usize = 0;
+    var c: usize = 0;
+    var d: usize = 0;
+
+    while (a < 2) {
+        print("a: {}\n", .{a});
+        a += 1;
+    }
+
+    while (b < 2) : (b += 1) {
+        print("b: {}\n", .{b});
+    }
+
+    while (c < 4) : ({
+        c += 1;
+        c += 1;
+    }) {
+        print("c: {}\n", .{c});
+    }
+
+    while (true) {
+        break;
+    }
+
+    while (true) : (d += 1) {
+        if (d < 2) {
+            print("d: {}\n", .{d});
+            continue;
+        }
+
+        break;
+    }
+}