[analyzer] Refactor visitPrefixExpression, visitNamedExpression, and visitParenthesizedExpression.

Change-Id: I5a5fa0897d25aab3092fc526342c5af12a67e0a5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/310770
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Kallen Tu <kallentu@google.com>

https://dart.googlesource.com/sdk/+/951d589c201e7fa2999cd0872933635b321c1e93