Revert of [wasm] Remove support for experimental version 0xD. (patchset #3...

Revert of [wasm] Remove support for experimental version 0xD. (patchset #3 id:40001 of https://codereview.chromium.org/2709753003/ )

Reason for revert:
Breaks layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/13730

Original issue's description:
> [wasm] Remove support for experimental version 0xD.
>
> R=mtrofin@chromium.org
> BUG=chromium:575167,chromium:694657
>
> Review-Url: https://codereview.chromium.org/2709753003
> Cr-Commit-Position: refs/heads/master@{#43368}
> Committed: https://chromium.googlesource.com/v8/v8/+/c8329253ea345e06a923f7800f96f4ef59262997

TBR=ahaas@chromium.org,mtrofin@chromium.org,titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:575167,chromium:694657

Review-Url: https://codereview.chromium.org/2706303004
Cr-Commit-Position: refs/heads/master@{#43373}

src/wasm/module-decoder.cc

@@ -272,7 +272,8 @@ class ModuleDecoder : public Decoder {
     pos = pc_;
     {
       uint32_t magic_version = consume_u32("wasm version");
-      if (magic_version != kWasmVersion) {
+      if (magic_version != kWasmVersion &&
+          magic_version != kWasmLegacyVersion) {
         error(pos, pos,
               "expected version %02x %02x %02x %02x, "
               "found %02x %02x %02x %02x",

src/wasm/module-decoder.h

@@ -16,6 +16,7 @@ namespace wasm {
 
 const uint32_t kWasmMagic = 0x6d736100;
 const uint32_t kWasmVersion = 0x01;
+const uint32_t kWasmLegacyVersion = 0x0d;  // TODO(titzer): remove 0xD!
 const uint8_t kWasmFunctionTypeForm = 0x60;
 const uint8_t kWasmAnyFunctionTypeForm = 0x70;
 const uint8_t kResizableMaximumFlag = 1;

test/mjsunit/wasm/jsapi-harness.js

@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// TODO(titzer): update spec test suite to version 0x1
-if (false) {
-
 // TODO(eholk): Once we have stable test IDs, use those as the key instead.
 // See https://github.com/WebAssembly/spec/issues/415
 const known_failures = {
@@ -79,5 +76,3 @@ last_promise.then(_ => {
     }
   }
 });
-
-}