Fix use of std::max when Windows.h is imported.

include/flatbuffers/flatbuffers.h

@@ -445,7 +445,7 @@ class vector_downward {
     if (len > static_cast<size_t>(cur_ - buf_)) {
       auto old_size = size();
       auto largest_align = AlignOf<largest_scalar_t>();
-      reserved_ += std::max(len, growth_policy(reserved_));
+      reserved_ += (std::max)(len, growth_policy(reserved_));
       // Round up to avoid undefined behavior from unaligned loads and stores.
       reserved_ = (reserved_ + (largest_align - 1)) & ~(largest_align - 1);
       auto new_buf = allocator_.allocate(reserved_);