cmake: enable warnings about initializer overrides
cmake: enable warnings about initializer overrides

This would have caught the double initialization of the "-" preallocated
string.

Signed-off-by: Josef 'Jeff' Sipek <a620f141433c70aa9e43778305a6c68cbfadfb25@josefsipek.net>

jeffpc/libjeffpc,jeffpc/libjeffpc,jeffpc/libjeffpc,jeffpc/libjeffpc