[Honor 8 ROMs, Kernels, Recoveries, & Other Develop] raz0rbl4de:
Grabbed some lines from logcat after an occasional reboot happened:

06-13 08:26:31.645 F/libc (10288): Fatal signal 6 (SIGABRT), code -6 in tid 10713 (FLP Service Cal)
06-13 08:26:31.738 F/DEBUG (12624): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
06-13 08:26:31.738 F/DEBUG (12624): LineageOS Version: 'unknown'
06-13 08:26:31.738 F/DEBUG (12624): Build fingerprint: 'HONOR/FRD-L09/HWFRD:7.0/HUAWEIFRD-L09/C432B380:user/release-keys'
06-13 08:26:31.738 F/DEBUG (12624): Revision: '0'
06-13 08:26:31.738 F/DEBUG (12624): ABI: 'arm64'
06-13 08:26:31.738 F/DEBUG (12624): pid: 10288, tid: 10713, name: FLP Service Cal >>> system_server <<<
06-13 08:26:31.738 F/DEBUG (12624): signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
06-13 08:26:31.741 F/DEBUG (12624): Abort message: 'art/runtime/indirect_reference_table.cc:132] JNI ERROR (app bug): local reference table overflow (max=512)'
06-13 08:26:31.742 F/DEBUG (12624): x0 0000000000000000 x1 00000000000029d9 x2 0000000000000006 x3 0000000000000008
06-13 08:26:31.742 F/DEBUG (12624): x4 0000000000000134 x5 0000800000000000 x6 0000007f7bd18000 x7 0000000000000000
06-13 08:26:31.742 F/DEBUG (12624): x8 0000000000000083 x9 ffffffffffffffdf x10 0000000000000000 x11 0000000000000001
06-13 08:26:31.742 F/DEBUG (12624): x12 ffffffffffffffff x13 0000000000000000 x14 0000000000000000 x15 00099c28926895aa
06-13 08:26:31.742 F/DEBUG (12624): x16 0000007f7a807ec8 x17 0000007f7a7b1828 x18 0000000000000000 x19 0000007f56cf54f8
06-13 08:26:31.742 F/DEBUG (12624): x20 0000000000000006 x21 0000007f56cf5450 x22 0000000000000000 x23 0000007f77d86a80
06-13 08:26:31.742 F/DEBUG (12624): x24 000000000000000a x25 ffffffffffffffff x26 000000000000037d x27 0000007f56cf36a1
06-13 08:26:31.742 F/DEBUG (12624): x28 0000007f77dfc760 x29 0000007f56cf35a0 x30 0000007f7a7aecd0
06-13 08:26:31.742 F/DEBUG (12624): sp 0000007f56cf3580 pc 0000007f7a7b1830 pstate 0000000060000000
06-13 08:26:31.748 F/DEBUG (12624):
06-13 08:26:31.748 F/DEBUG (12624): backtrace:
06-13 08:26:31.748 F/DEBUG (12624): #00 pc 000000000006c830 /system/lib64/libc.so (tgkill+8)
06-13 08:26:31.748 F/DEBUG (12624): #01 pc 0000000000069ccc /system/lib64/libc.so (pthread_kill+64)
06-13 08:26:31.748 F/DEBUG (12624): #02 pc 0000000000023ea0 /system/lib64/libc.so (raise+24)
06-13 08:26:31.748 F/DEBUG (12624): #03 pc 000000000001c924 /system/lib64/libc.so (abort+52)
06-13 08:26:31.748 F/DEBUG (12624): #04 pc 000000000043101c /system/lib64/libart.so (_ZN3art7Runtime5AbortEPKc+456)
06-13 08:26:31.748 F/DEBUG (12624): #05 pc 00000000000e5998 /system/lib64/libart.so (_ZN3art10LogMessageD2Ev+1576)
06-13 08:26:31.748 F/DEBUG (12624): #06 pc 000000000024c4e8 /system/lib64/libart.so (_ZN3art22IndirectReferenceTable3AddEjPNS_6mirror6ObjectE+308)
06-13 08:26:31.749 F/DEBUG (12624): #07 pc 0000000000349af4 /system/lib64/libart.so (_ZN3art3JNI9NewStringEP7_JNIEnvPKti+628)
06-13 08:26:31.749 F/DEBUG (12624): #08 pc 0000000000023e84 /system/lib64/libandroid_servers.so
06-13 08:26:31.749 F/DEBUG (12624): #09 pc 0000000000029960 /vendor/lib64/hw/flp.default.so
06-13 08:26:31.753 F/DEBUG (12624): #10 pc 0000000000014984 /vendor/lib64/hw/flp.default.so (_ZN8broadcom10FlpiClient25HandleFlpExtensionMessageERNS_18IpcIncomingMessageE+264)
06-13 08:26:31.753 F/DEBUG (12624): #11 pc 000000000001e02c /vendor/lib64/hw/flp.default.so (_ZN8broadcom20IpcPipeTransportBase8OnSelectEibbbPv+396)
06-13 08:26:31.753 F/DEBUG (12624): #12 pc 000000000001e7fc /vendor/lib64/hw/flp.default.so (_ZN8broadcom13SelectManager24PerformOneWaitAndProcessEv+588)
06-13 08:26:31.753 F/DEBUG (12624): #13 pc 0000000000013e1c /vendor/lib64/hw/flp.default.so (_ZN8broadcom15ipc_thread_procEPv+120)
06-13 08:26:31.753 F/DEBUG (12624): #14 pc 00000000000694d4 /system/lib64/libc.so (_ZL15__pthread_startPv+196)
06-13 08:26:31.753 F/DEBUG (12624): #15 pc 000000000001db38 /system/lib64/libc.so (__start_thread+16)
06-13 08:26:36.407 D/NetlinkEvent(10137): NL param 'DEVPATH=/devices/platform/hi_mci.2/mmc_host/mmc2/mmc2:0001/mmc2:0001:2/net/wlan0'
06-13 08:26:36.407 D/NetlinkEvent(10137): NL param 'WIFI_WAKE_PORT=60464'
06-13 08:26:36.408 D/NetlinkEvent(10137): NL param 'DEVTYPE=wlan'
06-13 08:26:36.408 D/NetlinkEvent(10137): NL param 'INTERFACE=wlan0'
06-13 08:26:36.408 D/NetlinkEvent(10137): NL param 'IFINDEX=13'
06-13 08:26:36.797 E/AndroidRuntime(360): FATAL EXCEPTION: main
06-13 08:26:36.797 E/AndroidRuntime(360): Process: com.google.android.googlequicksearchbox:search, PID: 360
06-13 08:26:36.797 E/AndroidRuntime(360): DeadSystemException: The system died; earlier logs will point to the root cause
06-13 08:26:37.573 E/FrameworkListener(10137): read() failed (Connection reset by peer)
06-13 08:26:37.840 E/AndroidRuntime(12601): FATAL EXCEPTION: EnsureDelegate
06-13 08:26:37.840 E/AndroidRuntime(12601): Process: com.facebook.katana, PID: 12601
06-13 08:26:37.840 E/AndroidRuntime(12601): DeadSystemException: The system died; earlier logs will point to the root cause

I can't pinpoint an exact reason for when this happens or how to recreate this. It reboots straight into the OS again. I've enabled FP unlock in Configurations so I can use the phone again immediately without any hassle (bypassing inserting the PIN/pattern instead of the fingerprint after a reboot).