byte-compile-enable-warning

byte-compile-enable-warning is an autoloaded compiled Lisp function in `bytecomp.el'.

(byte-compile-enable-warning WARNING)

Change `byte-compile-warnings' to enable WARNING.
If `byte-compile-warnings' is `t', do nothing. Otherwise, if the
first element is `not', remove WARNING, else add it.
Normally you should let-bind `byte-compile-warnings' before calling this,
else the global value will be modified.