Make it possible to provide generic dictionary layout externally (#4085)

...and implement a provider in the ILScanner.

This is a prerequisite for getting rid of generic lookup ready to run helpers.

* Add a `DictionaryLayoutProvider` class that provides `DictionaryLayoutNode` for a specified type or method.
* Expose APIs on compilation builder that let user specify a `DictionaryLayoutProvider` to be used for compilation.
* Add an implementation of `DictionaryLayoutProvider` on ILScanner that looks at the marked dictionary layouts in the graph to provide results.
* Make nodes that depend on dictionary layout to declare the dependency (so that it properly shows up in the graph)
* Add a lazy dictionary layout provider that just simulates the existing behavior of dictionary layouts that cannot be queried about slots until after we're done compiling.
* Duplicate dependencies from ReadyToRun generic helpers to dictionary layout/generic dictionaries - these have known dependencies if the slots are known. We'll need them when lookups stop using the ReadyToRun helpers.
* Implement Equals/GetHashCode on GenericLookupResult - these are normally interned, but when we reuse GenericLookupResults across scanning/compilation phase, we need to be able to compare them.

2 files changed, 3 insertions, 3 deletions

diff --git a/src/ILCompiler.CppCodeGen/src/Compiler/CppCodegenCompilationBuilder.cs b/src/ILCompiler.CppCodeGen/src/Compiler/CppCodegenCompilationBuilder.cs
index a9b278d40..fcd5c95cb 100644
--- a/src/ILCompiler.CppCodeGen/src/Compiler/CppCodegenCompilationBuilder.cs
+++ b/src/ILCompiler.CppCodeGen/src/Compiler/CppCodegenCompilationBuilder.cs
@@ -32,7 +32,7 @@ namespace ILCompiler
         public override ICompilation ToCompilation()
         {
             var interopStubManager = new CompilerGeneratedInteropStubManager(_compilationGroup, _context, new InteropStateManager(_compilationGroup.GeneratedAssembly));
-            CppCodegenNodeFactory factory = new CppCodegenNodeFactory(_context, _compilationGroup, _metadataManager, interopStubManager, _nameMangler, _vtableSliceProvider);
+            CppCodegenNodeFactory factory = new CppCodegenNodeFactory(_context, _compilationGroup, _metadataManager, interopStubManager, _nameMangler, _vtableSliceProvider, _dictionaryLayoutProvider);
             DependencyAnalyzerBase<NodeFactory> graph = CreateDependencyGraph(factory);
 
             return new CppCodegenCompilation(graph, factory, _compilationRoots, _logger, _config);
diff --git a/src/ILCompiler.CppCodeGen/src/Compiler/DependencyAnalysis/CppCodegenNodeFactory.cs b/src/ILCompiler.CppCodeGen/src/Compiler/DependencyAnalysis/CppCodegenNodeFactory.cs
index 0aa579bf7..5ba395683 100644
--- a/src/ILCompiler.CppCodeGen/src/Compiler/DependencyAnalysis/CppCodegenNodeFactory.cs
+++ b/src/ILCompiler.CppCodeGen/src/Compiler/DependencyAnalysis/CppCodegenNodeFactory.cs
@@ -11,8 +11,8 @@ namespace ILCompiler.DependencyAnalysis
     public sealed class CppCodegenNodeFactory : NodeFactory
     {
         public CppCodegenNodeFactory(CompilerTypeSystemContext context, CompilationModuleGroup compilationModuleGroup, MetadataManager metadataManager,
-            InteropStubManager interopStubManager, NameMangler nameMangler, VTableSliceProvider vtableSliceProvider)
-            : base(context, compilationModuleGroup, metadataManager, interopStubManager, nameMangler, new LazyGenericsDisabledPolicy(), vtableSliceProvider)
+            InteropStubManager interopStubManager, NameMangler nameMangler, VTableSliceProvider vtableSliceProvider, DictionaryLayoutProvider dictionaryLayoutProvider)
+            : base(context, compilationModuleGroup, metadataManager, interopStubManager, nameMangler, new LazyGenericsDisabledPolicy(), vtableSliceProvider, dictionaryLayoutProvider)
         {
         }