[Support] Use explicit inline element count for AccelerationStructureDescs SmallVectors

[MarijnS95]

Problem

AccelerationStructureDescs declares its lists with the default SmallVector inline element count:

struct AccelerationStructureDescs {
  llvm::SmallVector<BLASDesc> BLAS;
  llvm::SmallVector<TLASDesc> TLAS;
};

BLASDesc holds a std::string plus two further default-inlined SmallVectors (Triangles, AABBs), so its size compounds. Under MSVC's debug STL (/MDd, _ITERATOR_DEBUG_LEVEL=2), std::string and the nested inline storage grow enough that sizeof(BLASDesc) exceeds 256 bytes, tripping LLVM's assertion in CalculateSmallVectorDefaultInlinedElements:

You are trying to use a default number of inlined elements for SmallVector<T> but sizeof(T) is really big! Please use an explicit number of inlined elements with SmallVector<T, N> ...

This breaks any Debug build with MSVC on Windows (Pipeline.h is included widely). Release / RelWithDebInfo builds -- including CI -- keep the types under the limit, so the failure isn't visible there.

Fix

Give the lists an explicit inline element count, as the assertion recommends. Only BLASDesc trips the assert today; TLASDesc has the same shape and sits just under the threshold, so it gets the same treatment for consistency and to avoid a latent break when fields are added. No functional change -- this only sets inline storage capacity.

[bogner]

Merging this to get the post-commit CI green

[V-FEXrt]

LGTM