[mlir][CAPI] Introduce standard source layout for mlir-c dialect registration.
* Registers a small set of sample dialects.
* NFC with respect to existing C-API symbols but some headers have been moved down a level to the Dialect/ sub-directory.
* Adds an additional entry point per dialect that is needed for dynamic discovery/loading.
* See discussion: https://llvm.discourse.group/t/dialects-and-the-c-api/2306/16
Differential Revision: https://reviews.llvm.org/D94370
diff --git a/mlir/include/mlir-c/Dialect/Shape.h b/mlir/include/mlir-c/Dialect/Shape.h
new file mode 100644
index 0000000..f64da80
--- /dev/null
+++ b/mlir/include/mlir-c/Dialect/Shape.h
@@ -0,0 +1,25 @@
+//===-- mlir-c/Dialect/Shape.h - C API for Shape dialect ----------*- C -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM
+// Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_C_DIALECT_SHAPE_H
+#define MLIR_C_DIALECT_SHAPE_H
+
+#include "mlir-c/Registration.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+MLIR_DECLARE_CAPI_DIALECT_REGISTRATION(Shape, shape);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MLIR_C_DIALECT_SHAPE_H
