Allow mixing ranges and values to construct sequences

[edgarfgp]

Description

Implements RFC FS-1031: Mixing ranges and values to construct sequences fsharp/fslang-design#804

Before

let a = seq { yield! seq { 1..10 }; 19 }
let b = [-3; yield! [1..10]]
let c = [|-3; yield! [|1..10|]; 19|]

After

let a = seq { 1..10; 19 }
let b = [-3; 1..10]
let c = [|-3; 1..10; 19|]

Checklist

• Test cases added
• Add LanguageFeature
• RFC
• Release notes entry updated

[github-actions]

❗ Release notes required

---

✅ Found changes and release notes in following paths:

Change path	Release notes path	Description
src/Compiler	docs/release-notes/.FSharp.Compiler.Service/10.0.100.md
LanguageFeatures.fsi	docs/release-notes/.Language/preview.md

[edgarfgp]

/azp run

[azure-pipelines]

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