Augment the interface of ExternalASTSource::FindExternalLexicalDecls()
to allow clients to specify that they've already (correctly) loaded
declarations, and that no further action is needed. 

Also, make sure that we clear the "has external lexical declarations"
bit before calling FindExternalLexicalDecls(), to avoid infinite
recursion.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135306 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed