fix some bitfield size calculate bug

[qinghon]

Now, we can perceive non-starting bitfields and non-ending bitfields

Also, I modified the calculation method of align: only calculate alignment for bitfield from structure using bitfield_width
The reason is that the code now no longer relies on #[repr(C)] to generate alignments, but always contains all bytes
The problem that is currently known is that the test case bitfield-linux-32.hpp was dropped #[repr(packed(4))]. I don't know the reason, hope someone can help me

[qinghon]

Issue known to be repaired:
#1377
#3105
#743
#981
#1314

[qinghon]

r? @emilio

[rustbot]

Error: The feature assign is not enabled in this repository.
To enable it add its section in the triagebot.toml in the root of the repository.

Please file an issue on GitHub at triagebot if there's a problem with this bot, or reach out on #t-infra on Zulip.

[emilio]

Thanks! Generally it looks good but I suspect this is specific to 64-bit architectures? Or am I missing something? In any case some more comments would be good. Thanks

[qinghon]

fix and add #3104 case

this change add depended clang report offset

[qinghon]

@emilio Can you take some time to review this PR ？

[wdouglass]

Fixes #3238