[Fix #7849] Add ExplicitOperatorPrecedence cop

[rahul404]

Fixes #7849

This cop checks if binary operators of different precedents are used without explicit parenthesis.

# bad
a && b || c
a * b + c
a ** b * c / d % e + f - g << h >> i & j | k ^ l

# good
(a && b) || c
(a * b) + c
(((((a**b) * c / d % e) + f - g) << h >> i) & j) | k ^ l

[bbatsov]

@rahul404 I see the build is failing, so I assume this is still WIP. Let me know when it's ready for review.

[rahul404]

@bbatsov, The build fails due to a test case I am not able to figure out.

Hi @bbatsov, I have made a PR for this feature. There is one issue I can fix in it.
The test case to fix a ** b * c / d % e + f - g << h >> i & j | k ^ l fails. Somehow the cop exercises the correction method only once.
#7849 (comment)

[bbatsov]

I'm closing this PR due to no recent activity. Feel free to re-open it if you ever come back to it.