Add a basic TargetARM32 skeleton which knows nothing.

src/IceTargetLoweringARM32.def

Index: src/IceTargetLoweringARM32.def
diff --git a/src/IceTargetLoweringARM32.def b/src/IceTargetLoweringARM32.def
new file mode 100644
index 0000000000000000000000000000000000000000..baeec2c651d30866132ed51fe148fd94f5f78d77
--- /dev/null
+++ b/src/IceTargetLoweringARM32.def
@@ -0,0 +1,20 @@
+//===- subzero/src/IceTargetLoweringARM32.def - ARM32 X-macros --*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines certain patterns for lowering to ARM32 target
+// instructions, in the form of x-macros.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICETARGETLOWERINGARM32_DEF
+#define SUBZERO_SRC_ICETARGETLOWERINGARM32_DEF
+
+// TODO(jvoung): Fill out comparison tables, etc. for 32/64-bit compares.
+
+#endif // SUBZERO_SRC_ICETARGETLOWERINGARM32_DEF