Fix decoding mechanisms of the R5900

This series amends the R5900 support with the following changes:

- MFLO1, MFHI1, MTLO1 and MTHI1 are generated in gen_HILO1_tx79 instead of the generic gen_HILO.

- DIV1 and DIVU1 are generated in gen_div1_tx79 instead of the generic gen_muldiv.

- MOVN, MOVZ, MFHI, MFLO, MTHI, MTLO, MULT, MULTU, DIV, DIVU, DMULT, DMULTU, DDIV, DDIVU and JR are decoded in decode_opc_special_tx79 instead of the generic decode_opc_special_legacy.

- Guard check_insn_opc_user_only with INSN_R5900 check.

- Guard check_insn with INSN_R5900 check.

- Fix HI[ac] and LO[ac] 32-bit truncation with the MIPS64 DSP ASE.

This series has been successfully built with the 8 different build configurations

    {gcc,clang} x -m64 x mips{,64}el-{linux-user,softmmu}

in addition successfully completing the R5900 test suite

    cd tests/tcg/mips/mipsr5900 && make check

Changes in v2:
- Fix HI and LO 32-bit truncation with the MIPS64 DSP ASE
- Decode special R5900 opcodes in decode_opc_special_tx79
- Guard check_insn_opc_user_only with INSN_R5900 check
- Guard check_insn with INSN_R5900 check

Fredrik Noring (6):
target/mips: Fix decoding mechanism of R5900 MFLO1, MFHI1, MTLO1 and MTHI1 target/mips: Fix decoding mechanism of R5900 DIV1 and DIVU1 target/mips: Fix HI[ac] and LO[ac] 32-bit truncation with MIPS64 DSP ASE target/mips: Fix decoding mechanism of special R5900 opcodes target/mips: Guard check_insn_opc_user_only with INSN_R5900 check target/mips: Guard check_insn with INSN_R5900 check

 target/mips/translate.c | 229 +++++++++++++++++++++++++++++-----------
 1 file changed, 170 insertions(+), 59 deletions(-)

2.18.1