[runtimes] Move the enable_rtti Lit parameter to the DSL

GitOrigin-RevId: ff0d4367bf0b219fb69612f856892701eb2b1a8c
diff --git a/test/libunwind/test/config.py b/test/libunwind/test/config.py
index 31f6148..977f9a0 100644
--- a/test/libunwind/test/config.py
+++ b/test/libunwind/test/config.py
@@ -59,9 +59,6 @@
                                   % libunwind_headers)
         self.cxx.compile_flags += ['-I' + libunwind_headers]
 
-    def configure_compile_flags_rtti(self):
-        pass
-
     def configure_link_flags_cxx_library(self):
         # libunwind tests should not link with libc++
         pass