use tool_variable_check_load_default() FN with cc_* config vars especially in setup.cc.make.sh #8
Description
by using tool_variable_check_load_default, the every variable loaded by could automatically switch values by system arch and linux distribution.
so for example using cfg with ubuntu
cc_make_depends_ubuntu="bdb boost"
but debian by default
cc_make_depends_ubuntu="bdb"
or even
cc_make_depends_debian13="bdb"