This time actually fix big endian issue.

[Rot127]

Your checklist for this pull request

• [ ] I've documented or updated the documentation of every API function and struct this PR changes.
• [ ] I've added tests that prove my fix is effective or that my feature works (if possible)

Detailed description

Of course an enum value has the width of an int. If it is 64bits long and on a big endian machine, the enum value gets assigned to the upper bits. Not the lower ones.

Test plan

QEMU_LD_PREFIX=/usr/s390x-redhat-linux/sys-root/fc40/usr/ qemu-s390x-static ./build-s390x/cstool -d aarch64 01421bd501423bd5
 0  01 42 1b d5  msr    NZCV, x1
    ID: 734 (msr)
    op_count: 2
        operands[0].type: SYS REG:
        operands[0].subtype: REG_MSR = 0xda10
        operands[1].type: REG = x1
        operands[1].access: READ
    Update-flags: True
    Registers read: x1
    Groups: privilege 

 4  01 42 3b d5  mrs    x1, NZCV
    ID: 732 (mrs)
    op_count: 2
        operands[0].type: REG = x1
        operands[0].access: WRITE
        operands[1].type: SYS REG:
        operands[1].subtype: REG_MRS = 0xda10
    Registers modified: x1
    Groups: privilege 

Closing issues

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