tables
Currently in INSERT ... SELECT ... LIMIT ... the compiler uses a 
temporary table to store the results of SELECT ... LIMIT .. and then
uses that table as a source for INSERT. The problem is that in some cases
it actually skips the LIMIT clause in doing that and materializes the 
whole SELECT result set regardless of the LIMIT.
This fix is limiting the process of filling up the temp table with only 
that much rows that will be actually used by propagating the LIMIT value.