[wasm] Refactor import handling for 0xC.

test/mjsunit/wasm/ffi.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-wasm --allow-natives-syntax
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 function testCallFFI(func, check) {
@@ skipping 76 matching lines @@
   main_for_constructor_test = builder.instantiate({func: C}).exports.main;
 
   assertThrows("main_for_constructor_test(12, 43)", TypeError);
 }) ();
 
 print("Native function");
 (function test_ffi_call_to_native() {
 
   var builder = new WasmModuleBuilder();
 
-  var sig_index = builder.addType(kSig_d);
+  var sig_index = builder.addType(kSig_d_v);
   builder.addImport("func", sig_index);
   builder.addFunction("main", sig_index)
     .addBody([
       kExprCallFunction, 0  // --
     ])        // --
     .exportFunc();
 
   var main = builder.instantiate({func: Object.prototype.toString}).exports.main;
   // The result of the call to Object.prototype.toString should be
   // [object Undefined]. However, we cannot test for this result because wasm
@@ skipping 200 matching lines @@
       kExprCallFunction, 1   // --
     ])                       // --
     .exportFunc()
 
   var main = builder.instantiate({print: print}).exports.main;
   for (var i = -9; i < 900; i += 6.125) main(i);
 }
 
 testCallPrint();
 testCallPrint();