[Feature] Cached interceptor

[KyouyamaKazusa0805]

This issue will aim to C# experimental feature "interceptors" - to implement a method that will be replaced with new one in runtime, to change callsites.

using System;
using System.Runtime.CompilerServices;
using Test;

BaseType obj = new DerivedType();
obj.Do();

namespace Test
{
    file static class DerivedType_Intercepted
    {
        [InterceptsLocation("<file-path-here>", 6, 5)]
        public static void Do(this BaseType @this) => Console.WriteLine("intercepted.");
    }
}

namespace Test
{
    internal class BaseType
    {
        public virtual void Do() => Console.WriteLine(nameof(BaseType));
    }

    internal sealed class DerivedType : BaseType
    {
        public override void Do() => Console.WriteLine(nameof(DerivedType));
    }
}

namespace System.Runtime.CompilerServices
{
    [AttributeUsage(AttributeTargets.Method, Inherited = false)]
    file sealed class InterceptsLocationAttribute(string filePath, int line, int character) : Attribute
    {
        public string FilePath { get; } = filePath;

        public int Line { get; } = line;

        public int Character { get; } = character;
    }
}

This will make the result to be "intercepted." instead of "DerivedType".

For more information please visit this link.

---

To-do list:

• [x] API introduced
  • [x] Type CachedAttribute
  • [x] Type InterceptorMethodCallerAttribute
  • [x] Emit type InterceptsLocationAttribute
  • [x] Attribute targets only to method
  • [x] Constructor string filePath, int line, int character
  • [x] Constructor int version, string data
  • [x] Use source generation instead of concrete API
  • [x] Make accessibility internal instead of public to avoid confliction
• [x] Source generators
  • [x] Incremental generator CachedMethodGenerator
  • [ ] Syntax rewriter: CachedMethodSyntaxRewriter
  • [ ] Recognize grid properties that can be replaced with cached ones
  • [ ] Recognize instance method this references
  • [ ] Append this parameter if the target method is an instance method
• [ ] Supports
  • [x] Basic rules
  • [ ] Method signature sync
  • [x] Parameter types: TypeName parameter
  • [x] Parameter modifiers: ref readonly
  • [x] Parameter default values: = defaultValue
  • [x] Return types
    • [x] ref modifiers: ref readonly ReturnType
  • [ ] Nullability match
  • [ ] Generic type parameters
    • [ ] Declaration Method<T1, T2>
    • [ ] Arity match
    • [ ] Generic type parameter constraints: where T : notull, allows ref struct
  • [ ] Method types
  • [x] Static methods
  • [x] Instance methods
    • [x] Reference-typed this: Append parameter this ReferenceType @this
    • [x] Value-typed this: Append parameter this ValueType @this
    • [x] Append ref modifier: this ref ValueType @this
    • [x] Append scoped modifier: this scoped RefStructType @this
    • [x] Bind inheritance
      • [x] API added: [InterceptorInstanceTypes]
      • [x] Generate an extra entry method to route functions
      • [x] Backing generation
    • [ ] Accessing replacement: Replace 'this.member' and 'member' with '@this.member'
  • [ ] Other emit
  • [x] Indenting checking
  • [x] Syntax trivia correction
  • [ ] Others

[KyouyamaKazusa0805]

Finish for the first phase.