CONFIG_HAVE_KCSAN_COMPILER (not configurable)

configname: CONFIG_HAVE_KCSAN_COMPILER

Linux Kernel Configuration
└─>Kernel hacking
└─>Generic Kernel Debugging Instruments
└─>HAVE_KCSAN_COMPILER
In linux kernel since version 5.1 (release Date: 2019-05-05)  
For the list of compilers that support KCSAN, please see
Documentation/dev-tools/kcsan.rst.

is selected by
CONFIG_KCSAN