fix: resize Segment data_ to match capacity in ConcurrentArrayInvertedLists (#1641)

The Segment helper in ConcurrentArrayInvertedLists reserves data_'s
  capacity but never sizes it, so std::vector::size() stays 0 while
  operator[] reads and writes at offsets within capacity. That is
  undefined behavior; on a libstdc++ built with -D_GLIBCXX_ASSERTIONS,
  operator[] has a bounds check compiled in and the process aborts on
  the first growing-segment write (e.g. an IVF_FLAT_CC insert).

  Switch reserve() to resize() so size() == capacity() and operator[]
  is in-bounds. Same allocation, plus a zero-fill that the subsequent
  memcpy overwrites; no measurable runtime cost. Behavior on unhardened
  libstdc++ is unchanged.

Signed-off-by: Michael Paul <31833332+MickeyPvX@users.noreply.github.com>

Author: MickeyPvX

thirdparty/faiss/faiss/cppcontrib/knowhere/invlists/InvertedLists.h

@@ -162,7 +162,7 @@ struct ConcurrentArrayInvertedLists : ::faiss::InvertedLists, NormInvertedLists
     template <typename T>
     struct Segment {
         Segment(size_t segment_size, size_t code_size) : segment_size_(segment_size), code_size_(code_size) {
-            data_.reserve(segment_size_ * code_size_);
+            data_.resize(segment_size_ * code_size_);
         }
         T& operator[](idx_t idx) {
             assert(idx < segment_size_);