[libcxx-commits] [libcxx] [libc++] Document our ABI guarantees and what ABI flags exist to modify these guarantees (PR #132615)

[Louis Dionne via libcxx-commits]

================
@@ -38,84 +38,47 @@
 #endif
 
 #if _LIBCPP_ABI_VERSION >= 2
-// Change short string representation so that string data starts at offset 0,
-// improving its alignment in some cases.
-#  define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-// Fix deque iterator type in order to support incomplete types.
-#  define _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
-// Fix undefined behavior in how std::list stores its linked nodes.
+// TODO: Move the description of the remaining ABI flags to DesignDocs/ABIGuarantees.rst or remove them.
----------------
ldionne wrote:

```suggestion
// TODO: Move the description of the remaining ABI flags to ABIGuarantees.rst or remove them.
```

https://github.com/llvm/llvm-project/pull/132615