Fix an issue with writing to PCH another included PCH, introduced by the "using an AST on-disk hash table for name lookup" commit.

When including a PCH and later re-emitting to another PCH, the name lookup tables of DeclContexts
may be incomplete, since we now lazily deserialize the visible decls of a particular name.
Fix the issue by iterating over the un-deserialized visible decls and completing the lookup tables
of DeclContexts before writing them out.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111698 91177308-0d34-0410-b5e6-96231b3b80d8
9 files changed