tests) when using flex 2.5.31. The fix is to *not* try to use palloc
and pfree for allocations within the lexer; when you do that, the
yy_buffer_stack gets freed at inopportune times. The code is already
set up to do manual deallocation, so I see no particular advantage to
using palloc anyway.
yy_fatal_error() call results in elog(ERROR) not exit(). This was
already fixed in the main lexer and plpgsql, but extend same technique
to all the other dot-l files. Also, on review of the possible calls
to yy_fatal_error(), it seems safe to use elog(ERROR) not elog(FATAL).