Update Chapter 4 of the Toy tutorial

This Chapter now introduces and makes use of the Interface concept
in MLIR to demonstrate ShapeInference.
END_PUBLIC

Closes #191

PiperOrigin-RevId: 275085151
Change-Id: I1dac04d6d6a6c654a9873843998bac797a5d7e0f

third_party/mlir/include/mlir/Transforms/Passes.h

@@ -141,6 +141,9 @@ std::unique_ptr<OpPassBase<FuncOp>> createStripDebugInfoPass();
 /// Creates a pass which tests loop fusion utilities.
 std::unique_ptr<OpPassBase<FuncOp>> createTestLoopFusionPass();
 
+/// Creates a pass which inlines calls and callable operations as defined by the
+/// CallGraph.
+std::unique_ptr<Pass> createInlinerPass();
 } // end namespace mlir
 
 #endif // MLIR_TRANSFORMS_PASSES_H

third_party/mlir/lib/Transforms/Inliner.cpp

@@ -291,4 +291,8 @@ struct InlinerPass : public OperationPass<InlinerPass> {
 };
 } // end anonymous namespace
 
+std::unique_ptr<Pass> mlir::createInlinerPass() {
+  return std::make_unique<InlinerPass>();
+}
+
 static PassRegistration<InlinerPass> pass("inline", "Inline function calls");