Defer is now lowered in its own pass as a first step towards refactoring other things into their own passes as well

tests/test_break_continue_defer.krak

@@ -1,14 +1,21 @@
 import io:*
 
 fun main():int {
-    for (var i = 1; i < 10; i++;) {
-        {
-            defer println("happens every time, even when breaking or continueing")
-            if (i % 2 == 0)
-                continue
-            if (i == 9)
-                break
-            println(i)
+    {
+        defer println("block outside for")
+        for (var i = 1; i < 10; i++;) {
+            {
+                defer println("happens every time, even when breaking or continueing")
+                if (i % 2 == 0)
+                    continue
+                if (i == 9)
+                    break
+                if (i == 7) {
+                    defer println("only happens once before breaking 7")
+                    continue
+                }
+                println(i)
+            }
         }
     }
     {