Bug 282952 – prepare-commit-msg hook adds "Originally-landed-as" as a new trailer block

• Status: NEW
• Component: Tools / Tests

[Sam Sneddon [:gsnedders]]

prepare-commit-msg just does:

```
result += ['', 'Originally-landed-as: {}'.format(cherry_pick_metadata)]
```

This is notably less smart than how we canonicalize commits; see:

```
% git log bce91c8033e3^! d3ad1d842868^! --reverse
commit bce91c8033e3
Author: Kimmo Kinnunen <[e-mail]>
Date:   Wed Apr 24 09:22:12 2024 -0700

    WebGL fails to compile shaders with out variables that are arrays and start with underscore
    rdar://126944294
    
    Reviewed by Chris Dumez.
    
    Integrates upstream commit:
    commit e0e91b8cbb2e096d2d009cd0d1fbe20d785f2263
    Author: Kimmo Kinnunen <[e-mail]>
    Date:   Mon Apr 22 18:11:30 2024 -0700
    Metal: Fix rewritten out variables with underscores
    
    Fix compilation in case of output variables start with underscores.
    Make name emission always emit MSL name ANGLE_{name}, so that GLSL `_e`
    and `e` cannot clash. This regressed in angleproject:8558.
    
    Bug: b/335744344
    Change-Id: Ibae4dba4a24888acc1461582e69d48218ba11176
    Canonical link: https://commits.webkit.org/272448.959@safari-7618-branch

commit d3ad1d842868
Author: Kimmo Kinnunen <[e-mail]>
Date:   Thu May 16 12:18:12 2024 -0700

    WebGL fails to compile shaders with out variables that are arrays and start with underscore
    rdar://126944294
    
    Reviewed by Chris Dumez.
    
    Integrates upstream commit:
    commit e0e91b8cbb2e096d2d009cd0d1fbe20d785f2263
    Author: Kimmo Kinnunen <[e-mail]>
    Date:   Mon Apr 22 18:11:30 2024 -0700
    Metal: Fix rewritten out variables with underscores
    
    Fix compilation in case of output variables start with underscores.
    Make name emission always emit MSL name ANGLE_{name}, so that GLSL `_e`
    and `e` cannot clash. This regressed in angleproject:8558.
    
    Bug: b/335744344
    Change-Id: Ibae4dba4a24888acc1461582e69d48218ba11176
    
    Originally-landed-as: bce91c8033e3. rdar://128091308
    Canonical link: https://commits.webkit.org/278880@main
```

[Radar WebKit Bug Importer]

<rdar://problem/140152633>