KVM: x86: emulator: Fix illegal LEA handling

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2119111



commit 4ac5b423
Author: Michal Luczaj <mhal@rbox.co>
Date:   Fri Jul 29 15:48:01 2022 +0200

    KVM: x86: emulator: Fix illegal LEA handling

    The emulator mishandles LEA with register source operand. Even though such
    LEA is illegal, it can be encoded and fed to CPU. In which case real
    hardware throws #UD. The emulator, instead, returns address of
    x86_emulate_ctxt._regs. This info leak hurts host's kASLR.

    Tell the decoder that illegal LEA is not to be emulated.

Signed-off-by: Michal Luczaj <mhal@rbox.co>
    Message-Id: <20220729134801.1120-1-mhal@rbox.co>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>