55 new issues added in the Go analyzer

[sourya]

55 new issues, consisting of 36 bug risks and 19 antipatterns, have been added.

Some of the new issues that have been added are:

1. Violation of cgo pointer passing rules
   Attempts to pass a Go chan, map, func, or slice to C, either directly, or via a pointer, array, or struct is not recommended. This is because the values of these types (apart from zero-value) always contain Go pointers, which is not allowed by the cgo pointer passing rules.

2. Incorrect usage of sync/atomic package
   This issue is raised in case of redundant assignment after calling an atomic.Add* function.

3. sync.WaitGroup expected as a by-value parameter in a function or method
   Function parameters that are passed by value, are in fact a copy of the original argument. Passing a copy of a sync.WaitGroup is usually not what you’d want to do.

4. Possibly undesired value being used in goroutine
   Range variables in a loop are reused at each iteration; therefore a goroutine created in a loop will point to the range variable with from the upper scope. This way, the goroutine could use the variable with an undesired value. This rule warns when a range value (or index) is used inside a closure

5. Method expression can be replaced with method call
   It is simpler to use receiver functions of a type by calling them directly, rather than using selector syntax to select a function and then pass a receiver.