[libc++][ABI Break] Make is_error_condition_enum_v and is_error_code_enum_v bool, not size_t
`is_error_condition_enum_v` and `is_error_code_enum_v` are currently of
type `size_t`, but the standard mandates they are of type `bool`.
This is an ABI break technically since the size of these variable
templates has changed. Document it as such in the release notes.
Fixes https://bugs.llvm.org/show_bug.cgi?id=50755
Reviewed By: ldionne, Quuxplusone, #libc, var-const
Differential Revision: https://reviews.llvm.org/D112553
NOKEYCHECK=True
GitOrigin-RevId: 93df7b9f75af6b4282565e6e98bb306590375820
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index 7ad1923..d2713a9 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -78,6 +78,12 @@
exceeds the maximum supported size, as required by the C++ standard.
Previously the type ``std::length_error`` was used.
+ABI Changes
+-----------
+
+- The C++17 variable templates ``is_error_code_enum_v`` and
+ ``is_error_condition_enum_v`` are now of type ``bool`` instead of ``size_t``.
+
Build System Changes
--------------------