cpp11-migrate: Add headers to file override information

File override structures now contain per-source overrides for headers.

For now, modified headers are written to disk when the Migrator is done.
This is only temporary behaviour since we can expect headers to be
changed by migrating multiple source files. The changes need to be
merged after all migrations are complete.



git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@183917 91177308-0d34-0410-b5e6-96231b3b80d8
cpp11-migrate: const-correcting IncludeExcludeInfo

isFileIncluded() needed to be marked const.



git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@183918 91177308-0d34-0410-b5e6-96231b3b80d8