improve the check for the case
the pointer is assigned by parameter and the parameter is assigned by one pointer which is checked
add new test cases for "derefAfterAssignByArgument",
let's test the case, there are more than one reference call in the file
add testcase "tsStructDerefAndcheck"
move the old test case to the new things
add test case nullpointerExecutionPaths
add test case nullpointerExecutionPathsLoop
fix all the test cases