Issue #24266: Merge readline Ctrl+C handling from 3.5

diff --cc Misc/NEWS
index 6dfac97c24e9c17cbcc31d7fac5aada011809440,0058124e570dcea5f6f94612621fbc1690d46fb6..e6d69a29319f385f97b14bcf813fdc1bc3e6b95f
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -232,12 -93,10 +232,15 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #24266: Ctrl+C during Readline history search now cancels the search
+   mode when compiled with Readline 7.
+ 
 +- Issue #26590: Implement a safe finalizer for the _socket.socket type. It now
 +  releases the GIL to close the socket.
 +
 +- Issue #18787: spwd.getspnam() now raises a PermissionError if the user
 +  doesn't have privileges.
 +
  - Issue #26560: Avoid potential ValueError in BaseHandler.start_response.
    Initial patch by Peter Inglesby.
  

diff --cc Modules/readline.c
Simple merge