[WebAssembly] Initial WebAssembly backend

This WebAssembly backend is just a skeleton at this time and is not yet
functional.

llvm-svn: 241022
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMachineFunctionInfo.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMachineFunctionInfo.cpp
new file mode 100644
index 0000000..542d984
--- /dev/null
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyMachineFunctionInfo.cpp
@@ -0,0 +1,19 @@
+//=- WebAssemblyMachineFunctionInfo.cpp - WebAssembly Machine Function Info -=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file implements WebAssembly-specific per-machine-function
+/// information.
+///
+//===----------------------------------------------------------------------===//
+
+#include "WebAssemblyMachineFunctionInfo.h"
+using namespace llvm;
+
+WebAssemblyFunctionInfo::~WebAssemblyFunctionInfo() {}