[gn] Enable stricter build flags

test/cctest/test-strings.cc

Index: test/cctest/test-strings.cc
diff --git a/test/cctest/test-strings.cc b/test/cctest/test-strings.cc
index e4df339d8b62e92852c4d80ddbce530dd62cf656..2494df3c52136ca1b0dbc48c5fc1c4f649fa36f4 100644
--- a/test/cctest/test-strings.cc
+++ b/test/cctest/test-strings.cc
@@ -1114,16 +1114,9 @@ TEST(CachedHashOverflow) {
   v8::HandleScope handle_scope(CcTest::isolate());
   // Lines must be executed sequentially. Combining them into one script
   // makes the bug go away.
-  const char* lines[] = {
-      "var x = [];",
-      "x[4] = 42;",
-      "var s = \"1073741828\";",
-      "x[s];",
-      "x[s] = 37;",
-      "x[4];",
-      "x[s];",
-      NULL
-  };
+  const char* lines[] = {"var x = [];", "x[4] = 42;", "var s = \"1073741828\";",
+                         "x[s];",       "x[s] = 37;", "x[4];",
+                         "x[s];"};
 
   Handle<Smi> fortytwo(Smi::FromInt(42), isolate);
   Handle<Smi> thirtyseven(Smi::FromInt(37), isolate);
@@ -1136,9 +1129,9 @@ TEST(CachedHashOverflow) {
                                thirtyseven  // Bug yielded 42 here.
   };
 
-  const char* line;
   v8::Local<v8::Context> context = CcTest::isolate()->GetCurrentContext();
-  for (int i = 0; (line = lines[i]); i++) {
+  for (size_t i = 0; i < arraysize(lines); i++) {
+    const char* line = lines[i];
     printf("%s\n", line);
     v8::Local<v8::Value> result =
         v8::Script::Compile(context,