[WebAssembly] Add skeleton MC support for the Wasm container format

This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.

Differential Revision: https://reviews.llvm.org/D26722

llvm-svn: 295803
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetObjectFile.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetObjectFile.cpp
index 74e33b9..b1fd108 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetObjectFile.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetObjectFile.cpp
@@ -17,8 +17,14 @@
 #include "WebAssemblyTargetMachine.h"
 using namespace llvm;
 
-void WebAssemblyTargetObjectFile::Initialize(MCContext &Ctx,
-                                             const TargetMachine &TM) {
+void WebAssemblyTargetObjectFileELF::Initialize(MCContext &Ctx,
+                                                const TargetMachine &TM) {
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
   InitializeELF(TM.Options.UseInitArray);
 }
+
+void WebAssemblyTargetObjectFile::Initialize(MCContext &Ctx,
+                                             const TargetMachine &TM) {
+  TargetLoweringObjectFileWasm::Initialize(Ctx, TM);
+  InitializeWasm();
+}