Update version gcc -> cc and buildgen

[vit1251]

Changes:

• Replace gcc -> cc crate
• Update buildgen version

Known issues:

1. No Error in this scope

error[E0412]: cannot find type `Error` in this scope
  --> src/result.rs:1:1
   |
1  | / error_chain! {
2  | |     foreign_links {
3  | |         ::std::io::Error, IoError;
4  | |     }
...  |
15 | |     }
16 | | }
   | |_^ not found in this scope

2. No default implementation

error[E0277]: the trait bound `drm_shim::drm_mode_destroy_dumb: Default` is not satisfied
   --> src/ffi/mod.rs:248:46
    |
248 |         let mut raw: drm_mode_destroy_dumb = Default::default();
    |                                              ^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `drm_shim::drm_mode_destroy_dumb`