[libc++] Rename the -fno-rtti Lit feature to just no-rtti

This is consistent to the way we name other Lit features, and it removes
the possibility for confusing the Lit feature with the actual compiler
flag.

GitOrigin-RevId: f9e70fa546a461b3c9fa8463efcd9f7fe989bd9f
diff --git a/test/incomplete_type.sh.cpp b/test/incomplete_type.sh.cpp
index fba24b2..5521a10 100644
--- a/test/incomplete_type.sh.cpp
+++ b/test/incomplete_type.sh.cpp
@@ -14,7 +14,7 @@
 // addresses.
 
 // UNSUPPORTED: no-exceptions
-// UNSUPPORTED: -fno-rtti
+// UNSUPPORTED: no-rtti
 
 // NOTE: Link libc++abi explicitly and before libc++ so that libc++ doesn't drag
 // in the system libc++abi installation on OS X. (DYLD_LIBRARY_PATH is ignored