[analyzer][CrossTU][NFC] Generalize to external definitions instead of external functions

Summary: This is just changing naming and documentation to be general about external definitions that can be imported for cross translation unit analysis. There is at least a plan to add VarDecls: D46421

Reviewers: NoQ, xazax.hun, martong, a.sidorin, george.karpenkov, serge-sans-paille

Reviewed By: xazax.hun, martong

Subscribers: mgorny, whisperity, baloghadamsoftware, szepet, rnkovacs, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, cfe-commits

Differential Revision: https://reviews.llvm.org/D56441

llvm-svn: 350852
diff --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
index e61b4bb..ace0b81 100644
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -63,8 +63,8 @@
 tools = [
     'c-index-test', 'clang-check', 'clang-diff', 'clang-format', 'clang-tblgen',
     'opt',
-    ToolSubst('%clang_func_map', command=FindTool(
-        'clang-func-mapping'), unresolved='ignore'),
+    ToolSubst('%clang_extdef_map', command=FindTool(
+        'clang-extdef-mapping'), unresolved='ignore'),
 ]
 
 if config.clang_examples: