Hooking up asm-wasm conversion.

src/arm/builtins-arm.cc

Index: src/arm/builtins-arm.cc
diff --git a/src/arm/builtins-arm.cc b/src/arm/builtins-arm.cc
index a8e1df3b4d5dc46c21c850737bd2cfd825de330e..2fd792a01bd3c398f88bcc22eb320f447da1047f 100644
--- a/src/arm/builtins-arm.cc
+++ b/src/arm/builtins-arm.cc
@@ -1418,6 +1418,48 @@ void Builtins::Generate_CompileOptimizedConcurrent(MacroAssembler* masm) {
   GenerateTailCallToReturnedCode(masm, Runtime::kCompileOptimized_Concurrent);
 }
 
+void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- r0 : argument count (preserved for callee)
+  //  -- r1 : new target (preserved for callee)
+  //  -- r3 : target function (preserved for callee)
+  // -----------------------------------
+  Label failed;
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    // Push the number of arguments to the callee.
+    __ SmiTag(r0);
+    __ push(r0);
+    // Push a copy of the target function and the new target.
+    __ push(r1);
+    __ push(r3);
+
+    // The function.
+    __ push(r1);
+    // Copy arguments from caller (stdlib, foreign, heap).
+    for (int i = 2; i >= 0; --i) {
+      __ ldr(r4, MemOperand(fp, StandardFrameConstants::kCallerSPOffset +
+                                    i * kPointerSize));
+      __ push(r4);
+    }
+    // Call runtime, on success unwind frame, and parent frame.
+    __ CallRuntime(Runtime::kInstantiateAsmJs, 4);
+    // A smi 0 is returned on failure, an object on success.
+    __ JumpIfSmi(r0, &failed);
+    scope.GenerateLeaveFrame();
+    __ Drop(4);
+    __ Ret();
+
+    __ bind(&failed);
+    // Restore target function and new target.
+    __ pop(r3);
+    __ pop(r1);
+    __ pop(r0);
+    __ SmiUntag(r0);
+  }
+  // On failure, tail call back to regular js.
+  GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
+}
 
 static void GenerateMakeCodeYoungAgainCommon(MacroAssembler* masm) {
   // For now, we are relying on the fact that make_code_young doesn't do any