We have an operator expression like `x * 5`. We want to follow where the
value of the operator expression goes. We used to follow local flow from
an operand, but now there is flow from that operand to the next use of
the variable. The fix is to explicitly start local flow from the
operator expression.
There are also some expected edge changes due to use-use flow.
The extra nodes in .expected files are due to the changes from
https://github.com/github/codeql/pull/13717, which are not applied to
configuration classes extending DataFlow::Configuration or
TaintTracking::Configuration.
