Fix variable declaration access graphs

[Christian Dürr]

Currently the calculated access graph does not create an edge between a variable declaration and the value it has been assigned.

var test = foo;

In the above example, an edge should be created marking test as an accessor of foo.

There are already two tests for this which are currently ignored:

javascript::lang::accesses::tests::leaked_renamed_function
javascript::lang::accesses::tests::parenthesized_variable