[release-branch.go1.26] go/analysis/passes/modernize: add vendored code

[release-branch.go1.26] go/analysis/passes/modernize: add vendored code

Note this is a sum of CLs 731340, 733180, and 736715.

Fixes #77529
Fixes #77624

Change-Id: I0c8119877184d2e6506d0b34895a746bafed3829
Reviewed-on: https://go-review.googlesource.com/c/go/+/746360
Reviewed-by: Madeline Kalil <mkalil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>