invalid anchors when passing a typeclass to `grind`

Prerequisites

• Check that your issue is not already filed:
  https://github.com/leanprover/lean4/issues
• Reduce the issue to a minimal, self-contained, reproducible test case.
  Avoid dependencies to Mathlib or Batteries.
• Test your test case against the latest nightly release, for example on
  https://live.lean-lang.org/#project=lean-nightly
  (You can also use the settings there to switch to “Lean nightly”)

Description

For a call directly using a typeclass, grind? will fail to report the class and also include invalid anchors.

Steps to Reproduce

An example:

example {α} {r : α → α → Prop} [Std.Refl r] (a : α) : r a a := by
  grind [Std.Refl]

where none of the grind? suggestions work for these reasons.

Expected behavior:

grind? includes the passed typeclass, and no invalid anchors.

Actual behavior:

Each grind? suggestion is either an empty grind only or has invalid anchors.

Versions

Lean 4.30.0-rc2
Target: x86_64-unknown-linux-gnu

Impact

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Start by reproducing the minimal Lean example with grind? on the specified nightly release, then compare the generated suggestions with the expected behavior. The issue is done when the passed typeclass is included and the suggestions contain no invalid anchors or empty grind only commands.