[libcxx-commits] [libcxx] Unify naming of internal pointer members in std::vector and std::__split_buffer (PR #115517)

[Louis Dionne via libcxx-commits]

ldionne wrote:

The bootstrapping build failures are legitimate (the other ones are not). They are caused by the fact that we store a `__split_buffer` inside `deque` and changing the name of the variable [breaks the LLDB data formatters](https://github.com/llvm/llvm-project/actions/runs/11746523395/job/32728376148?pr=115517).

I think the following diff should fix it, but @Michael137 should chime in to let us know if LLDB generally tries to be more backwards-compatible than what this diff achieves:

```diff
diff --git a/lldb/examples/synthetic/libcxx.py b/lldb/examples/synthetic/libcxx.py
index b078a4eb2f63..f8534cf9fdc9 100644
--- a/lldb/examples/synthetic/libcxx.py
+++ b/lldb/examples/synthetic/libcxx.py
@@ -765,7 +765,7 @@ class stddeque_SynthProvider:
                 )
             else:
                 map_endcap = map_.GetChildMemberWithName(
-                    "__end_cap_"
+                    "__cap_"
                 ).GetValueAsUnsigned(0)
 
             # check consistency
```

https://github.com/llvm/llvm-project/pull/115517