How to find default kotlin compiler argument values?

Question

Currently I use a bunch of compiler flags in my gradle build file. I'm sure some of these are defaults that I would prefer not to specify explicitly (and thereby have them updated automatically as the compiler is updated).

But I cannot find any documentation on default values for various compiler options. How to determine them?

kotlinOptions {
    languageVersion = "1.5"
    apiVersion = "1.5"
    jvmTarget = '11'
    useIR = true
}