private Varnode getConstantOrExternal(VarnodeContext vContext, Address minInstrAddress,
			Varnode val1) {
		Varnode vt;
		if (!context.isExternalSpace(val1.getSpace())) {
			Long lval = vContext.getConstant(val1, evaluator);
			if (lval == null) {
				return null;
			}
			vt = vContext.getVarnode(minInstrAddress.getAddressSpace().getSpaceID(), lval, 0);
		}
		else {
			vt = val1;
		}
		return vt;
	}
Apply pcode from an instruction to current varnode context.
Following a flow will push a new context state based on the current context state onto the contextStack

@param contextStack context state stack
@param vContext varnode context
@param instruction instruction to apply pcode from
@param continueAfterHittingFlow true if should continue after hitting an already processed flow
@param monitor to cancel
@return true to to continue this instruction path, false otherwise
Ghidra/Features/Base/src/main/java/ghidra/program/util/SymbolicPropogator.java