vmx_emulate_cr0_access() sets EFER.LMA and the IA-32e guest VM-entry
control when enabling paging with EFER.LME set, but does not clear them
when disabling paging. This can leave an inconsistent guest state that
fails VM entry.
Update both fields in either direction based on EFER.LME and the CR0
value written to the VMCS. Use the mask-adjusted CR0 value so the
resulting state remains consistent with the VMX fixed-bit requirements.
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