default or selected kernelversion does not have config value CONFIG_GENERIC_ASHLDI3.
Result is shown for kernelversion 6.4.14

CONFIG_GENERIC_ASHLDI3 (not configurable)

modulename: ashldi3.ko

configname: CONFIG_GENERIC_ASHLDI3

Linux Kernel Configuration
└─>GENERIC_ASHLDI3
In linux kernel since version 4.9.8 (release Date: 2017-02-04)  
source code:
lib/ashldi3.c