Suppress trim and AOT diagnostics in Dapper fallback paths

[JamesNK]

Fixes #2232.

Summary

Add method-level UnconditionalSuppressMessage attributes for the reflection, runtime generic construction, and DynamicMethod paths reported by the Dapper.AOT-enabled Native AOT dashboard application:

• DefaultTypeMap property/field discovery and inherited property setter lookup (IL2070, IL2075).
• StructuredHelper.CreateFor provider-specific structured parameters (IL2070, IL3050).
• SqlMapper.AddTypeHandlerCore and LookupDbType runtime generic construction (IL3050).
• SqlMapper.CreateParamInfoGenerator runtime parameter-object generation (IL2075, IL3050).
• TypeExtensions.GetPublicInstanceMethod framework method lookup (IL2070).

Includes an internal compatibility definition of UnconditionalSuppressMessageAttribute for the legacy target frameworks. No public signatures or execution paths change.

This is a diagnostic-suppression change, not an AOT-safe rewrite: it does not preserve reflected members, root arbitrary generic instantiations, or remove the fallback implementations from the reachable graph. Unsupported fallback usage remains unsupported.

Validation

• dotnet build .\Dapper\Dapper.csproj --no-restore succeeded for net461, netstandard2.0, net8.0, and net10.0.
• The standalone Dapper.AOT/SQLite sample below published for win-x64 with Native AOT and zero Dapper IL diagnostics. The check included all Dapper IL warning IDs, not just the three reported in the issue.
• Running the published native executable printed 42.
• SDK used: 11.0.100-rc.1.26425.128; sample target framework: net10.0.
• The sample restore/publish also reported NU1903 for transitive SQLitePCLRaw.lib.e_sqlite3 2.1.11 (advisory). This was separate from the Dapper IL diagnostics; these are the exact package versions tested, not a dependency-version recommendation.
• Full test suite attempted with dotnet test .\tests\Dapper.Tests\Dapper.Tests.csproj --no-restore --framework net10.0: 66 passed, 30 skipped, 704 failed. SQL Server connection failures were reported because the required database instance was unavailable, so the full suite is not validated as passing.
• No source diagnostics were reported for the changed files. CRLF-aware git diff --check passed.

The standalone sample was created outside the repository and is included below rather than added to the solution. It validates the scalar DynamicParameters scenario; the full Aspire dashboard was not republished for this patch.

DapperIssue2232.csproj

This is the project used for validation. Adjust the absolute ProjectReference to point to the Dapper checkout being tested.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net10.0</TargetFramework>
    <PublishAot>true</PublishAot>
    <TrimmerSingleWarn>false</TrimmerSingleWarn>
    <InterceptorsNamespaces>$(InterceptorsNamespaces);Dapper.AOT</InterceptorsNamespaces>
  </PropertyGroup>
  <ItemGroup>
    <ProjectReference Include="C:\Development\Source\Dapper\Dapper\Dapper.csproj" />
    <PackageReference Include="Dapper.AOT" Version="1.1.0" />
    <PackageReference Include="Microsoft.Data.Sqlite" Version="10.0.8" />
  </ItemGroup>
</Project>

Program.cs

using System;
using Dapper;
using Microsoft.Data.Sqlite;

[module: DapperAot]

using var connection = new SqliteConnection("Data Source=:memory:");
connection.Open();

var parameters = new DynamicParameters();
parameters.Add("Value", 42);
Console.WriteLine(connection.QuerySingle<int>("select @Value", parameters));

Publish And Run

Run from the standalone sample directory with the Windows Native AOT build prerequisites installed:

dotnet publish .\DapperIssue2232.csproj -c Release -r win-x64 --self-contained true -p:ContinuousIntegrationBuild=false
.\bin\Release\net10.0\win-x64\publish\DapperIssue2232.exe

Observed native executable output:

42

[JamesNK]

Vibe coded. Please double check this is good. I'm not very fimilar about how Dapper and Dapper.AOT interact.