Add aggressive inlining support for generated mapping methods

[Kataane]

Add aggressive inlining support for generated mapping methods

Description

This pull request adds support for applying MethodImplOptions.AggressiveInlining to generated mapping methods, allowing users to optimize performance based on their specific needs.

Key changes:

• Added AggressiveInliningTypes enum with None, ValueTypes, ReferenceTypes, and All options
• Added AggressiveInliningTypes property to MapperAttribute for configuration
• Updated mapping method generation to conditionally apply [MethodImpl(MethodImplOptions.AggressiveInlining)] attribute
• Extended unsafe accessor generation to support aggressive inlining
• Added comprehensive test coverage for all aggressive inlining scenarios

Technical details:
The implementation introduces a new configuration option that allows users to control when aggressive inlining should be applied to generated mapping methods. This is particularly useful for performance-critical scenarios where the overhead of method calls can be significant.

The feature supports granular control:

• None: No aggressive inlining (default, maintains backward compatibility)
• ValueTypes: Apply to struct mappings only
• ReferenceTypes: Apply to class mappings only
• All: Apply to all mappings

Example usage:

[Mapper(AggressiveInliningTypes = AggressiveInliningTypes.All)]
public partial class MyMapper
{
    public partial TargetDto Map(SourceEntity source);
}

Performance impact:
This feature allows users to achieve better performance in scenarios where mapping methods are called frequently, especially for simple mappings where the method call overhead is significant compared to the mapping logic itself.

Checklist

• The existing code style is followed
• The commit message follows our guidelines
• Performed a self-review of my code
• Hard-to-understand areas of my code are commented
• The documentation is updated (as applicable)
• Unit tests are added/updated
• Integration tests are added/updated (as applicable, especially if feature/bug depends on roslyn or framework version in use)

Related Issues

#1384

[latonz]

Have you measured the impact of this? Does it significantly improve the performance? Does this already work if the user applies the attribute to the user declared method?

[Kataane]

Hi @latonz

Have you measured the impact of this?
Does it significantly improve the performance

According to previous measurements, #1384:

• 27x faster for simple struct types
• 1.3x faster for complex struct types
• Very slightly faster for class types

If you want, I can rerun the benchmark to ensure the result is repeated.

---

Does this already work if the user applies the attribute to the user declared method

It works for all methods in the mapping class if her is one of the AggressiveInliningTypes types:

[Mapper(EnumMappingStrategy = EnumMappingStrategy.ByName, AggressiveInliningTypes = AggressiveInliningTypes.All)]
public static partial class CarMapper
{
    [MapProperty(nameof(Car.Manufacturer), nameof(CarDto.Producer))]
    public static partial CarDto MapCarToDto(Car car);

    public static partial int ToInt(int value);
}