Support literal attribute on decimals

[esbenbjerre]

The intention of this PR is to add support for the use of the literal attribute on decimals.

[<Literal>]
let d = 2.5m

• Allow decimal constant in PostInferenceChecks
• Add decimal arithmetic in TypedTreeOps
• Add DecimalConstantAttribute to TcGlobals
• Add codegen (initonly field with attribute + cctor) to IlxGen
• Fix broken tests
• Add test for pattern matching a value against a decimal literal (IL, compileAndRun)
• Add test for incomplete pattern matching a value against a decimal literal
• Add test for usage and evaluation of decimal literal in quotations (compileAndRun)
• Test C# interop

Related fsharp/fslang-suggestions#847

[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/9.0.200.md

[esbenbjerre]

@dotnet-policy-service agree

[T-Gro]

Hi @esbenbjerre , thanks for this contribution.
Here are a few test areas I would expect to be covered as part of this PR:

• Pattern matching a value against a decimal literal (IL test, compileAndRun test)
• Incomplete Pattern matching with decimal literals
• Usage and evaluation of decimal literal in quotations (compileAndRun test)
• Consumption of the literal in C# (multiproject test for interop), tooling support from C# (referencing a .dll with the decimal constant in a C# project from IDE)

[esbenbjerre]

Thanks @T-Gro. I'm still trying to codegen the cctor code. Would you prefer I convert it to draft until it's ready?

[vzarytovskii]

Yeah, let's convert it to draft so it doesn't pop up on our triage radar