The regression is caused by the fix for bug 14767. When INSERT ... SELECT
used a view in the SELECT list that was not inlined, and there was an 
active transaction, the server could crash in Query_cache::invalidate.

On INSERT ... SELECT only the table being inserted into is invalidated.
Thus views that can't be inlined are skipped from invalidation.

The bug manifests itself in two ways so there is 2 test cases.
One checks that the only the table being inserted into is invalidated.
And the second one checks that there is no crash on INSERT ... SELECT.


mysql-test/t/query_cache.test:
  Added a test case for bug#20045: Server crash on INSERT ... SELECT ... FROM non-mergeable view
mysql-test/r/query_cache.result:
  Added a test case for bug#20045: Server crash on INSERT ... SELECT ... FROM non-mergeable view
sql/sql_parse.cc:
  Bug#20045: Server crash on INSERT ... SELECT ... FROM non-mergeable view 
  On INSERT ... SELECT only the table being inserted into is invalidated.