TemplateTemplateParmDecls of alias templates ended-up serialized as 'file-level decls' which was causing a crash while trying to index a PCH/module file that contained them.
Commit makes sure TemplateTemplateParmDecls are not recorded as such kind of decls.
Fixes crash of rdar://36608297
Differential Revision: https://reviews.llvm.org/D42588
llvm-svn: 323549