[libcxx] [llvm] [libc++][CI] Tests the no RTTI configuration. (PR #65518)

[Louis Dionne via llvm-commits]

================
@@ -284,7 +284,9 @@ endif()
 
 # Feature options -------------------------------------------------------------
 option(LIBCXX_ENABLE_EXCEPTIONS "Use exceptions." ON)
-option(LIBCXX_ENABLE_RTTI "Use run time type information." ON)
+option(LIBCXX_ENABLE_RTTI
+  "Use run time type information.
----------------
ldionne wrote:

```suggestion
  "Use runtime type information.
```

https://github.com/llvm/llvm-project/pull/65518