[clang] Introduce paged vector (PR #66430)

[Vassil Vassilev via cfe-commits]

================
@@ -1625,6 +1625,39 @@ SmallVector has grown a few other minor advantages over std::vector, causing
    and is no longer "private to the implementation". A name like
    ``SmallVectorHeader`` might be more appropriate.
 
+.. _dss_pagedvector:
+
+llvm/ADT/PagedVector.h
+^^^^^^^^^^^^^^^^^^^^^^
+
+``PagedVector<Type, PageSize>`` is a random access container that allocates
+(PageSize) elements of type Type when the first element of a page is accessed
----------------
vgvassilev wrote:

```suggestion
``PageSize`` elements of type ``Type`` when the first element of a page is accessed
```

https://github.com/llvm/llvm-project/pull/66430