[wasm] Store the function_index in the js-to-wasm wrapper instead of the export index

test/mjsunit/wasm/wasm-constants.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
 
 function bytes() {
   var buffer = new ArrayBuffer(arguments.length);
   var view = new Uint8Array(buffer);
   for (var i = 0; i < arguments.length; i++) {
@@ skipping 76 matching lines @@
 let kExternalFunction = 0;
 let kExternalTable = 1;
 let kExternalMemory = 2;
 let kExternalGlobal = 3;
 
 let kTableZero = 0;
 let kMemoryZero = 0;
 
 // Useful signatures
 let kSig_i_i = makeSig([kAstI32], [kAstI32]);
+let kSig_l_l = makeSig([kAstI64], [kAstI64]);
 let kSig_i_l = makeSig([kAstI64], [kAstI32]);
 let kSig_i_ii = makeSig([kAstI32, kAstI32], [kAstI32]);
 let kSig_i_iii = makeSig([kAstI32, kAstI32, kAstI32], [kAstI32]);
 let kSig_d_dd = makeSig([kAstF64, kAstF64], [kAstF64]);
 let kSig_l_ll = makeSig([kAstI64, kAstI64], [kAstI64]);
 let kSig_i_dd = makeSig([kAstF64, kAstF64], [kAstI32]);
 let kSig_v_v = makeSig([], []);
 let kSig_i_v = makeSig([], [kAstI32]);
 let kSig_l_v = makeSig([], [kAstI64]);
 let kSig_f_v = makeSig([], [kAstF64]);
@@ skipping 258 matching lines @@
         eval(code);
       }
     } catch (e) {
       assertEquals("number", typeof e);
       assertEquals(value, e);
       // Success.
       return;
     }
     throw new MjsUnitAssertionError("Did not throw at all, expected: " + value);
 }