Ordo-one/benchmark aggregated allocation stacks

Hey everyone! Benchmark now supports allocation-stack recording for easily tracking down root causes of memory allocations. An allocation-stack shows the chain of function calls that led to a heap allocation, helping you identify which code paths allocate most often. Allocation-stack recording requires the default-enabled MallocInterposer trait and a toolchain providing Swift’s Runtime module. On macOS, it requires macOS 26 or later. Recording adds overhead, so this diagnostic mode measures onl...