Fixed memory leak.

Fixed memory leak.

Found by valgrind:

 1,177 bytes in 1 blocks are definitely lost in loss record 1 of 1
    at 0x4C2AE40: operator new[](unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
    by 0x42153F: re2c::cfg_t::compact(re2c::cfg_t const&, int*) (compact.cc:12)
    by 0x422088: re2c::optimize_tags(re2c::dfa_t&) (optimize.cc:18)
    by 0x42DE3A: re2c::compile(re2c::spec_t const&, re2c::Output&) (compile.cc:82)
    by 0x446742: re2c::parse(re2c::Scanner&, re2c::Output&) (parser.ypp:484)
    by 0x402DC0: main (main.cc:38)