[modules] When building a module, make sure we don't serialize out...

[modules] When building a module, make sure we don't serialize out HeaderFileInfo for headers not belonging to the module.

After r180934 we may initiate module map parsing for modules not related to the module what we are building,
make sure we ignore the header file info of headers from such modules.

First part of rdar://13840148

llvm-svn: 181489