Reapply r259210 with a fix for RegistryTest.cpp.

Patch by Richard Thomson.

llvm-svn: 259359
diff --git a/clang/lib/ASTMatchers/Dynamic/Registry.cpp b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
index 6aee484..df4f29d 100644
--- a/clang/lib/ASTMatchers/Dynamic/Registry.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -182,6 +182,7 @@
   REGISTER_MATCHER(forStmt);
   REGISTER_MATCHER(friendDecl);
   REGISTER_MATCHER(functionDecl);
+  REGISTER_MATCHER(functionProtoType);
   REGISTER_MATCHER(functionTemplateDecl);
   REGISTER_MATCHER(functionType);
   REGISTER_MATCHER(gotoStmt);