Auto merge of #468 - flier:padding-bytes, r=emilio

Improve struct alignment with padding bytes

I known, it is a little tricky or dirty solution, I have to do a lot of calculate for alignment.

For example
```c++
typedef struct {
  long long __clang_max_align_nonce1
      __attribute__((__aligned__(__alignof__(long long))));
  long double __clang_max_align_nonce2
      __attribute__((__aligned__(__alignof__(long double))));
} max_align_t;
```
will be generated as
```rust
pub struct _bindgen_ty_1 {
    pub __clang_max_align_nonce1: ::std::os::raw::c_longlong,
    _padding_0: u64,
    pub __clang_max_align_nonce2: f64,
    _padding_1: u64,
}
fn bindgen_test_layout__bindgen_ty_1() {
    assert_eq!(::std::mem::size_of::<_bindgen_ty_1>() , 32usize);
    assert_eq! (0usize , unsafe {
                & ( * ( 0 as * const _bindgen_ty_1 ) ) .
                __clang_max_align_nonce1 as * const _ as usize });
    assert_eq! (16usize , unsafe {
                & ( * ( 0 as * const _bindgen_ty_1 ) ) .
                __clang_max_align_nonce2 as * const _ as usize });
}
```
It may generate wrong layout when use template or multi virtual inheritance.

At least, it is a begining, pass all the test cases, and some [complex struct](https://github.com/servo/rust-bindgen/compare/master...flier:padding-bytes?expand=1#diff-eda352138aed047149ebeec72d19979d) in wild.

0 files changed, 0 insertions, 0 deletions