git-clang-format

Ah! Now I understand why my local run keeps missing these formatting
changes. It's because by default it only does C++ formatting on files
that end in `.cpp`, so it doesn't search `string` by default, which is
where I keep making changes. It's not that CI is running a more
up-to-date clang-format which disagrees on style. It's that it's using
a longer command line which reminds it to check extensionless C++
standard headers.

Author: statham-arm

libcxx/include/string

@@ -853,7 +853,10 @@ private:
     value_type v;
   };
   enum { __union_alignment = _LIBCPP_ALIGNOF(__union_alignment_check) };
-  enum { __full_size = (static_cast<size_t>(__short_packed_size) + static_cast<size_t>(__union_alignment) - 1) & -static_cast<size_t>(__union_alignment) };
+  enum {
+    __full_size = (static_cast<size_t>(__short_packed_size) + static_cast<size_t>(__union_alignment) - 1) &
+                -static_cast<size_t>(__union_alignment)
+  };
 
   // Now define both structures for real, with padding to ensure they are both
   // exactly the calculated size.
@@ -875,7 +878,8 @@ private:
 
   struct __short {
     value_type __data_[__min_cap];
-    _LIBCPP_NO_UNIQUE_ADDRESS __padding<static_cast<size_t>(__full_size) - static_cast<size_t>(__short_packed_size)> __padding_;
+    _LIBCPP_NO_UNIQUE_ADDRESS __padding<static_cast<size_t>(__full_size) - static_cast<size_t>(__short_packed_size)>
+        __padding_;
     unsigned char __size_    : 7;
     unsigned char __is_long_ : 1;
   };