Fix handling of reraise in effect tracking (#10582)

This is the MVP in order not to get a completely useless error message
from the compiler.

Fixes #10579

tests/effects/teffects8.nim

@@ -0,0 +1,12 @@
+discard """
+  errormsg: "can raise an unlisted exception: Exception"
+  line: 10
+"""
+
+proc foo() {.raises: [].} =
+  try:
+    discard
+  except ValueError:
+    raise
+
+foo()