swift

9d59044b - [BrdigingHeader] Auto bridging header chaining

[BrdigingHeader] Auto bridging header chaining Add ability to automatically chaining the bridging headers discovered from all dependencies module when doing swift caching build. This will eliminate all implicit bridging header imports from the build and make the bridging header importing behavior much more reliable, while keep the compatibility at maximum. For example, if the current module A depends on module B and C, and both B and C are binary modules that uses bridging header, when building module A, dependency scanner will construct a new header that chains three bridging headers together with the option to build a PCH from it. This will make all importing errors more obvious while improving the performance.