Implement redeclaration merging for namespaces defined in distinct
modules. Teach name lookup into namespaces to search in each of the
merged DeclContexts as well as the (now-primary) DeclContext. This
supports the common case where two different modules put something
into the same namespace.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147778 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed