Currently we keep only one NativeCallStack data for every node in the VMATree. In the NMT detail mode, the reports show call-stacks per reserve and commit operations. Therefore, a commit. that starts with reserved-region base will overwrite the call-stack of the reserve operation. Example:

reserved region: 100-150, call-stack: function_1
committed: 100-120, call_stack: function_2

function_1 is overwritten by function_2 for node 100.
both function_1 and function_2 should be available during reports.