PCH serialization/deserialization of the source manager. With this
improvement, source locations read from the PCH file will properly
resolve to the source files that were used to build the PCH file
itself.

Once we have the preprocessor state stored in the PCH file, source
locations that refer to macro instantiations that occur in the PCH
file should have the appropriate instantiation information.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68758 91177308-0d34-0410-b5e6-96231b3b80d8
11 files changed