[date] Add ICU backend for timezone info behind a flag

test/mjsunit/testcfg.py

Index: test/mjsunit/testcfg.py
diff --git a/test/mjsunit/testcfg.py b/test/mjsunit/testcfg.py
index 7af7acf0a927e2ac034aa459cd4aaa796618ea14..869ab26b5bc6f7b25d7cd1d5115293da450d66d6 100644
--- a/test/mjsunit/testcfg.py
+++ b/test/mjsunit/testcfg.py
@@ -33,6 +33,7 @@ from testrunner.objects import testcase
 
 FLAGS_PATTERN = re.compile(r"//\s+Flags:(.*)")
 FILES_PATTERN = re.compile(r"//\s+Files:(.*)")
+ENV_PATTERN = re.compile(r"//\s+Environment Variables:(.*)")
 SELF_SCRIPT_PATTERN = re.compile(r"//\s+Env: TEST_FILE_NAME")
 MODULE_PATTERN = re.compile(r"^// MODULE$", flags=re.MULTILINE)
 NO_HARNESS_PATTERN = re.compile(r"^// NO HARNESS$", flags=re.MULTILINE)
@@ -94,6 +95,12 @@ class MjsunitTestSuite(testsuite.TestSuite):
       flags.append("--isolate")
       flags += files
 
+    env_match = ENV_PATTERN.search(source)
+    if env_match:
+      for env_pair in env_match.group(1).strip().split():
+        var, value = env_pair.split('=')
+        testcase.env[var] = value
+
     return testcase.flags + flags
 
   def GetSourceForTest(self, testcase):