Add a regression test for an already fixed issue.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index b40b8208df4401adfb37afc80fb3c725e20271d5..35264b9085628ab62ebb6747321aa81bf486ed38 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -5065,7 +5065,7 @@ bool Heap::ConfigureHeap(int max_semispace_size,
     if (max_semispace_size < Page::kPageSize) {
       max_semispace_size = Page::kPageSize;
       if (FLAG_trace_gc) {
-        PrintF("Max semispace size cannot be less than %dkbytes",
+        PrintF("Max semispace size cannot be less than %dkbytes\n",
                Page::kPageSize >> 10);
       }
     }
@@ -5081,7 +5081,7 @@ bool Heap::ConfigureHeap(int max_semispace_size,
     if (max_semispace_size_ > reserved_semispace_size_) {
       max_semispace_size_ = reserved_semispace_size_;
       if (FLAG_trace_gc) {
-        PrintF("Max semispace size cannot be more than %dkbytes",
+        PrintF("Max semispace size cannot be more than %dkbytes\n",
                reserved_semispace_size_ >> 10);
       }
     }