Add some scaffolding for parsing affine maps:
- parsing affine map identifiers
- place-holder classes for AffineMap
- module contains a list of affine maps (defined at the top level).
PiperOrigin-RevId: 202336919
diff --git a/lib/IR/AffineExpr.cpp b/lib/IR/AffineExpr.cpp
new file mode 100644
index 0000000..63d8d7d
--- /dev/null
+++ b/lib/IR/AffineExpr.cpp
@@ -0,0 +1,23 @@
+//===- AffineExpr.cpp - MLIR Affine Expr Classes --------------------------===//
+//
+// Copyright 2019 The MLIR Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// =============================================================================
+
+#include "mlir/IR/AffineExpr.h"
+
+using namespace mlir;
+
+AffineExpr::AffineExpr() {
+}