[ci] Split browser64_4gb into its own runner

Also add test_TextDecoder to the list of test.

Author: sbc100

.circleci/config.yml

@@ -805,11 +805,14 @@ jobs:
     steps:
       - run-tests-chrome:
           title: "browser64"
-          # skip test_4gb_fail as it OOMs on the current bot
-          # Run a few tests in browser64_4gb mode too.
+          test_targets: "browser64"
+  test-browser-chrome-wasm64_4gb:
+    executor: bionic
+    steps:
+      - run-tests-chrome:
+          title: "browser64_4gb"
           test_targets: "
-            browser64
-            skip:browser64.test_4gb_fail
+            browser64_4gb.test_TextDecoder*
             browser64_4gb.test_async_*
             browser64_4gb.test_audio_worklet*
             browser64_4gb.test_emscripten_log

test/test_browser.py

@@ -4555,7 +4555,6 @@ def test_utf8_textdecoder(self):
   def test_utf16_textdecoder(self):
     self.btest_exit('benchmark/benchmark_utf16.cpp', 0, args=['--embed-file', test_file('utf16_corpus.txt') + '@/utf16_corpus.txt', '-sEXPORTED_RUNTIME_METHODS=[UTF16ToString,stringToUTF16,lengthBytesUTF16]'])
 
-  @no_wasm64()
   @parameterized({
     '': ([],),
     'closure': (['--closure=1'],),