Merge branch 'gcc-debug' into 'master'

Add -g to generate debuginfo on gcc

See merge request redox-os/cookbook!634

src/bin/cook.rs

@@ -883,6 +883,8 @@ then
     install_flags=--debug
     build_flags=
     build_type=debug
+    export CFLAGS="${CFLAGS} -g"
+    export CPPFLAGS="${CPPFLAGS} -g"
 fi
 
 # cargo template