target-tricore: Add instructions of RR opcode format, that have 0x4b as the first...

target-tricore: Add instructions of RR opcode format, that have 0x4b as the first opcode

Add instructions of RR opcode format, that have 0x4b as the first opcode.
Add helper functions:
    * parity: Calculates the parity bits for every byte of a 32 int.
    * bmerge/bsplit: Merges two regs into one bitwise/Splits one reg into two bitwise.
    * unpack: unpack a IEEE 754 single precision floating point number as exponent and mantissa.
    * dvinit_b_13/131: (ISA v1.3/v1.31)Prepare operands for a divide operation,
                       where the quotient result is guaranteed to fit into 8 bit.
    * dvinit_h_13/131: (ISA v1.3/v1.31)Prepare operands for a divide operation,
                       where the quotient result is guaranteed to fit into 16 bit.
OPCM_32_RR_FLOAT -> OPCM_32_RR_DIVIDE.

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>