[wasm][asm.js] Forbid function declaration replacing variable declaration.

test/cctest/asmjs/test-asm-typer.cc

 // Copyright 2016 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.
 
 #include <cstring>
 #include <functional>
 #include <iostream>
 #include <memory>
 
 #include "src/asmjs/asm-typer.h"
@@ skipping 654 matching lines @@
       {"return d2s_tbl;", "cannot export function tables"},
       {"return min;", "cannot export standard library functions"},
       {"return ffi;", "cannot export foreign functions"},
       {"return I;", "is not an asm.js function"},
       {"return {'a': d2s_tbl}", "cannot export function tables"},
       {"return {'a': min}", "cannot export standard library functions"},
       {"return {'a': ffi}", "cannot export foreign functions"},
       {"return {'a': f()}", "must be an asm.js function name"},
       {"return {'a': f}", "Undefined identifier in asm.js module export"},
       {"function v() { a(); } return {b: d2s}", "Missing definition for forw"},
-      {"return {b: d2s, 'a': d2s_tbl}", "cannot export function tables"},
-      {"return {b: d2s, 'a': min}", "cannot export standard library"},
-      {"return {b: d2s, 'a': ffi}", "cannot export foreign functions"},
-      {"return {b: d2s, 'a': f()}", "must be an asm.js function name"},
-      {"return {b: d2s, 'a': f}", "Undefined identifier in asm.js module"},
+      {"function v() {} return {b: v, 'a': d2s_tbl}",
+       "cannot export function tables"},
+      {"function v() {} return {b: v, 'a': min}",
+       "cannot export standard library"},
+      {"function v() {} return {b: v, 'a': ffi}",
+       "cannot export foreign functions"},
+      {"function v() {} return {b: v, 'a': f()}",
+       "must be an asm.js function name"},
+      {"function v() {} return {b: v, 'a': f}",
+       "Undefined identifier in asm.js module"},
   };
 
   auto d2s_tbl = [](Zone* zone) -> iw::AsmType* {
     auto* d2s = iw::AsmType::Function(zone, iw::AsmType::Signed());
     d2s->AsFunctionType()->AddArgument(iw::AsmType::Double());
 
     auto* ret = iw::AsmType::FunctionTableType(zone, 2, d2s);
     return ret;
   };
 
-  auto d2s = [](Zone* zone) -> iw::AsmType* {
-    auto* ret = iw::AsmType::Function(zone, iw::AsmType::Signed());
-    ret->AsFunctionType()->AddArgument(iw::AsmType::Double());
-    return ret;
-  };
-
   for (size_t ii = 0; ii < arraysize(kTests); ++ii) {
     const auto* test = kTests + ii;
     if (!ValidationOf(Export(test->module_export))
              ->WithGlobal(DynamicGlobal("d2s_tbl"), d2s_tbl)
-             ->WithGlobal(DynamicGlobal("d2s"), d2s)
              ->WithImport(DynamicGlobal("min"), iw::AsmTyper::kMathMin)
              ->WithImport(DynamicGlobal("ffi"), iw::AsmTyper::kFFI)
              ->WithGlobal(DynamicGlobal("I"), iw::AsmType::Int())
              ->FailsWithMessage(test->error_message)) {
       std::cerr << "Test:\n" << test->module_export;
       CHECK(false);
     }
   }
 }
 
@@ skipping 1338 matching lines @@
     if (!ValidationOf(Module(kTests[ii]))
              ->FailsWithMessage(
                  "Constant in return must be signed, float, or double.")) {
       std::cerr << "Test:\n" << kTests[ii];
       CHECK(false);
     }
   }
 }
 
 }  // namespace