Support -strict in test arguments (#10039)

We cannot yet enable this for all of GWT's own tests, see #10038 for
that followup. That said, that failure confirms that this feature is
working as expected.

Fixes #10037

Author: niloc132

user/src/com/google/gwt/junit/JUnitShell.java

@@ -60,6 +60,7 @@
 import com.google.gwt.dev.util.arg.ArgHandlerScriptStyle;
 import com.google.gwt.dev.util.arg.ArgHandlerSetProperties;
 import com.google.gwt.dev.util.arg.ArgHandlerSourceLevel;
+import com.google.gwt.dev.util.arg.ArgHandlerStrict;
 import com.google.gwt.dev.util.arg.ArgHandlerWarDir;
 import com.google.gwt.dev.util.arg.ArgHandlerWorkDirOptional;
 import com.google.gwt.junit.JUnitMessageQueue.ClientStatus;
@@ -299,6 +300,7 @@ public int handle(String[] args, int tagIndex) {
       registerHandler(new ArgHandlerFilterJsInteropExports(options));
       registerHandler(new ArgHandlerSetProperties(options));
       registerHandler(new ArgHandlerClosureFormattedOutput(options));
+      registerHandler(new ArgHandlerStrict(options));
 
       /*
        * ----- Options specific to JUnitShell -----

user/test/com/google/gwt/junit/JUnitShellTest.java

@@ -45,7 +45,7 @@ public void testDefaultModuleUrl() throws Exception {
   public void testArgOptimize() throws Exception {
     parseGoodArgs("-optimize", "8", "-XdisableInlineLiteralParameters",
         "-XdisableRemoveDuplicateFunctions", "-XdisableClusterSimilarFunctions",
-        "-XdisableOrdinalizeEnums", "-XdisableOptimizeDataflow");
+        "-XdisableOrdinalizeEnums", "-XdisableOptimizeDataflow", "-strict");
   }
 
   private void parseGoodArgs(String... argsToUse) {