[WebAssembly] Register wasm passes with the PassRegistry

Summary:
This exposes WebAssembly passes for use on the command line (as
arguments to -print-before and the like).

Reviewers: dschuff, sunfish

Subscribers: MatzeB, jfb, sbc100, llvm-commits, aheejin

Differential Revision: https://reviews.llvm.org/D45103

llvm-svn: 328901
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblySetP2AlignOperands.cpp b/llvm/lib/Target/WebAssembly/WebAssemblySetP2AlignOperands.cpp
index c4b9e91..429f94e 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblySetP2AlignOperands.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblySetP2AlignOperands.cpp
@@ -46,6 +46,10 @@
 } // end anonymous namespace
 
 char WebAssemblySetP2AlignOperands::ID = 0;
+INITIALIZE_PASS(WebAssemblySetP2AlignOperands, DEBUG_TYPE,
+                "Set the p2align operands for WebAssembly loads and stores",
+                false, false)
+
 FunctionPass *llvm::createWebAssemblySetP2AlignOperands() {
   return new WebAssemblySetP2AlignOperands();
 }