public int getStackPurge() {
		return stackPurge;
	}
Follow the flows of the subroutine, accumulating information about the
stack pointer and any other register the stack pointer is assigned to.

@param func
           function to analyze
@param monitor
           monitor to provide feedback and cancel
@throws CancelledException if monitor canceled
Ghidra/Features/Base/src/main/java/ghidra/app/cmd/function/CallDepthChangeInfo.java