[EH] Fix printing bug in nested blocks + delegate (#4753)

`controlFlowDepth` is a variable used to print `delegate`'s target. When
printing nested blocks, we increase `controlFlowDepth` by the number of
nested blocks at once. But we should decrement it as we finish each
block, rather than decrease by the number of nested blocks at once,
because we need correct `controlFlowDepth` within nested blocks.

1 files changed, 13 insertions, 0 deletions

diff --git a/test/exception-handling.wast b/test/exception-handling.wast
index 1db356684..642856f03 100644
--- a/test/exception-handling.wast
+++ b/test/exception-handling.wast
@@ -352,4 +352,17 @@
       )
     )
   )
+
+  ;; When 'delegate' is next to a nested block, make sure its delegate argument
+  ;; is parsed correctly.
+  (func $nested-block-and-try
+    (block $l0
+      (block $l1)
+      (try
+        (do)
+        (delegate 1) ;; to caller
+      )
+    )
+    (nop)
+  )
 )