Increase code space allowance for first page size.

test/cctest/test-spaces.cc

Index: test/cctest/test-spaces.cc
diff --git a/test/cctest/test-spaces.cc b/test/cctest/test-spaces.cc
index 85b33c9cf0531d586e0b7ca8cc8ff0b2a7d40dc7..3f5e437223a57ba246c093ce8ce4d0ea7d061fcc 100644
--- a/test/cctest/test-spaces.cc
+++ b/test/cctest/test-spaces.cc
@@ -439,6 +439,9 @@ TEST(SizeOfFirstPageIsLargeEnough) {
   if (!isolate->snapshot_available()) return;
   if (Snapshot::EmbedsScript(isolate)) return;
 
+  // If this test fails due to enabling experimental natives that are not part
+  // of the snapshot, we may need to adjust CalculateFirstPageSizes.
+
   // Freshly initialized VM gets by with one page per space.
   for (int i = FIRST_PAGED_SPACE; i <= LAST_PAGED_SPACE; i++) {
     // Debug code can be very large, so skip CODE_SPACE if we are generating it.