Summary:
This patch improves support of PDB as an external layout source
in the next cases:
- Multiple non-virtual inheritance from packed base classes. When using
external layout, there's no need to align `NonVirtualSize` of a base class.
It may cause an overlapping when the next base classes will be layouted
(but there is a slightly different case in the test because I can't find
a way to specify a base offset);
- Support of nameless structs and unions. There is no info about nameless child
structs and unions in Microsoft cl-emitted PDBs. Instead all its fields
are just treated as outer structure's (union's) fields. This also causes
a fields overlapping, and makes it possible for unions to have fields located
at a non-zero offset.
Reviewers: rsmith, zturner, rnk, mstorsjo, majnemer
Reviewed By: rnk
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D49871
llvm-svn: 338353