Issue #21523: Fix over-pessimistic computation of the stack effect of some opcodes...

This also fixes a quadratic compilation time issue noticeable when compiling
code with a large number of "and" and "or" operators.

diff --cc Misc/NEWS
index 76006d908748db37c70080bbf2a34305bf18ba72,c1033868581962c4d35a2c5a649c0f72b9d93acf..7e55c2138a68729c065d31dbe7d8644fcc7df3fa
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,6 -10,20 +10,11 @@@ Release date: TB
  Core and Builtins
  -----------------
  
 -
 -What's New in Python 3.4.1?
 -===========================
 -
 -Release date: 2014-05-18
 -
 -Core and Builtins
 ------------------
 -
+ - Issue #21523: Fix over-pessimistic computation of the stack effect of
+   some opcodes in the compiler.  This also fixes a quadratic compilation
+   time issue noticeable when compiling code with a large number of "and"
+   and "or" operators.
+ 
  - Issue #21418: Fix a crash in the builtin function super() when called without
    argument and without current frame (ex: embedded Python).
  

diff --cc Python/compile.c
Simple merge