Export - makefile templates - Wextra

[0xc0170]

I would like to enable flag -Wextra to CC_FLAGS. The library is build with this flag, as defined in gcc.py script.

But templates for gcc_arm does not contain this option (I checked few). I might look at this, and start fixing warnings.

[chrta]

I could add this flag in #1159. Only one file must be adapted for that. Maybe -pedantic would be good, too.

[adamgreen]

👍 for -Wextra
👎 for -pedantic

[0xc0170]

@chrta Send separate PR for that extra flag, after the current refactoring of gcc make templates is on master. Thanks

[chrta]

This issue is fixed after merging #1251