Changes in CRC detection v5:

Changes in CRC detection v5:

      - If before/after xor there is shift with other value than one, don't say it's not CRC.
      - In the list of acceptable operations between xor and shift added minus and plus operations.

    Changes in Traverse and execute CRC function v9:
      - Check INTEGER_CST case in assign statement
      - Deleted gcc/symb-execute-all-paths.cc/h.

    Changes in LFSR matching v5:
      - Added check for crc^data^1 and crc^data^1 neighbor bits case.
      - Refactored check_xor_right_1_case function.

    Changes in LFSR creation v2:
      - Added last_set_bit function, to get last set bit of the polynomial and create smaller LFSR if needed.
      - Create crc_value without new, and don't delete.
      - Delete lfsr at the end.

    Added crc-25.c, crc-callerid.c, crc-cc1541.c tests.