Combine for loop and while loop tests into the same file (#135)

tests/should_succeed/loops.jou

@@ -0,0 +1,62 @@
+from "stdlib/io.jou" import printf
+
+# No warning or error for missing return statement.
+# But we can't call this function as it loops infinitely.
+def foo() -> int:
+    while True:
+        printf("Hi\n")
+
+def main() -> int:
+    # Output: 0
+    # Output: 1
+    # Output: 2
+    i = 0
+    while i < 3:
+        printf("%d\n", i++)
+
+    # Output: 0
+    # Output: 1
+    # Output: 2
+    for i = 0; i < 3; i++:
+        printf("%d\n", i)
+
+    # Output: 0->1 1->2 2->3 3->end
+    i = 0
+    while True:
+        printf("%d->", i)
+        if i == 3:
+            printf("end\n")
+            break
+            printf("yooooooo\n")  # Warning: this code will never run
+        printf("%d ", ++i)
+
+    # Output: 0->1->2->3->end
+    for i = 0; True; i++:
+        printf("%d->", i)
+        if i == 3:
+            printf("end\n")
+            break
+            printf("yooooooo\n")  # Warning: this code will never run
+
+    # Output: 0...4...8.
+    i = 0
+    while i < 10:
+        if i % 4 != 0:
+            printf(".")
+            i++
+            continue
+            printf("yooooooo\n")  # Warning: this code will never run
+        printf("%d", i)
+        i++
+    printf("\n")
+
+    # Output: 0...4...8.
+    for i = 0; i < 10; i++:
+        if i % 4 != 0:
+            printf(".")
+            continue
+            printf("yooooooo\n")  # Warning: this code will never run
+        printf("%d", i)
+    printf("\n")
+
+    return 0