Fix bug with -MM -MG.

PR preprocessor/15220
* files.c (_cpp_find_file): New parameter angle_brackets.  Fix all
callers.  Pass to open_file_failed.
(open_file_failed): New parameter angle_brackets.  Fix all callers.
Use in print_dep assignment.
* init.c (cpp_read_main_file): Pass additional arg to _cpp_find_file.
* internal.h (_cpp_find_file): Add new parm to declaration.

From-SVN: r105757
diff --git a/libcpp/init.c b/libcpp/init.c
index 8d564c9..3074f96 100644
--- a/libcpp/init.c
+++ b/libcpp/init.c
@@ -467,7 +467,7 @@
     }
 
   pfile->main_file
-    = _cpp_find_file (pfile, fname, &pfile->no_search_path, false);
+    = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0);
   if (_cpp_find_failed (pfile->main_file))
     return NULL;