CONFIG_UNWINDER_ARM is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

ARM EABI stack unwinder

configname: CONFIG_UNWINDER_ARM

Choose kernel unwinder
└─>ARM EABI stack unwinder
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This option enables stack unwinding support in the kernel
using the information automatically generated by the
compiler. The resulting kernel image is slightly bigger but
the performance is not affected. Currently, this feature
only works with EABI compilers.