private void cacheInstruction(Address addr, Instruction instr) {
		instructionAtCache.put(addr, instr);
		if (instr != null) {
			instructionContainingCache.put(instr.getMaxAddress(), instr);
			// pre-fill the pcode cache for this instructions
			getInstructionPcode(instr);
		}
	}
Check that we haven't hit a run of the same exact instruction.
   Uses hashcodes in an attempt to be as fast as possible.
@param instr new instruction to check
@return true if we have hit the max number of exact same instructions.
Ghidra/Features/Base/src/main/java/ghidra/program/util/SymbolicPropogator.java