Fix RequiresDynamicCode warnings in OleDb

[agocke]

This specifically addresses IL3050 warnings (ones generated as part of AOT-compat). Contributes to #75480

[Copilot]

Pull Request Overview

This PR fixes RequiresDynamicCode warnings (IL3050) in the OleDb library to improve AOT compatibility. The changes primarily involve adding RequiresDynamicCode attributes to classes and methods that use dynamic code generation features like Marshal.GetDelegateForFunctionPointer and other reflection-based operations.

Key changes include:

• Adding RequiresDynamicCode attributes to various OleDb classes and methods
• Converting Marshal.SizeOf(typeof(T)) calls to generic Marshal.SizeOf<T>() versions
• Updating Marshal.StructureToPtr and similar methods to use generic overloads
• Enabling AOT compatibility by setting IsAotCompatible to true in the project file

Reviewed Changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
System.Data.OleDb.csproj	Enables AOT compatibility by setting IsAotCompatible to true
DbMetaDataFactory.cs	Adds RequiresDynamicCode attribute to constructor
DbConnectionHelper.cs	Adds RequiresDynamicCode attribute to ConnectionFactory getter
DbBuffer.cs	Converts StructureToPtr method to use generics for AOT compatibility
OleDb_Util.cs	Updates Marshal.SizeOf calls to use generic versions
OleDbWrapper.cs	Converts Marshal.GetDelegateForFunctionPointer calls to generic versions and adds class-level attribute
OleDbTransaction.cs	Adds RequiresDynamicCode attributes to class and methods
OleDbMetaDataFactory.cs	Adds RequiresDynamicCode attributes to class and constructor
OleDbFactory.cs	Adds RequiresDynamicCode attribute to class
OleDbEnumerator.cs	Adds conditional RequiresDynamicCode attributes to methods
OleDbDataReader.cs	Adds RequiresDynamicCode attributes to class and methods
OleDbDataAdapter.cs	Adds RequiresDynamicCode attribute to class
OleDbConnectionStringBuilder.cs	Adds conditional RequiresDynamicCode attributes to class and methods
OleDbConnectionInternal.cs	Adds conditional RequiresDynamicCode attributes throughout and updates Marshal.PtrToStructure calls
OleDbConnectionFactory.cs	Adds RequiresDynamicCode attribute and suppression for metadata factory
OleDbConnection.cs	Adds RequiresDynamicCode attribute to class and defines trim warning constant
OleDbCommand.cs	Adds RequiresDynamicCode attribute to class
CompatibilitySuppressions.xml	Adds suppressions for compatibility differences in reference assemblies
System.Data.OleDb.cs	Updates reference assembly with conditional RequiresDynamicCode attributes

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[jtschuster]

For the types with Requires on the type definition, IIRC they shouldn't also need annotations on their instance or static methods.