PPC: fix allocation issues for PPC64.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/1009433002

Cr-Commit-Position: refs/heads/master@{#27179}

src/snapshot-common.cc

@@ -135,6 +135,8 @@ void CalculateFirstPageSizes(bool is_default_snapshot,
       required = (startup_reservations[startup_index].chunk_size() +
                   2 * context_reservations[context_index].chunk_size()) +
                  Page::kObjectStartOffset;
+      // Add a small allowance to the code space for small scripts.
+      if (space == CODE_SPACE) required += 32 * KB;
     } else {
       // We expect the vanilla snapshot to only require on page per space.
       DCHECK(!is_default_snapshot);

test/cctest/test-strings.cc

@@ -1209,7 +1209,7 @@ UNINITIALIZED_TEST(OneByteArrayJoin) {
   v8::Isolate::CreateParams create_params;
   // Set heap limits.
   create_params.constraints.set_max_semi_space_size(1);
-  create_params.constraints.set_max_old_space_size(5);
+  create_params.constraints.set_max_old_space_size(6);
   v8::Isolate* isolate = v8::Isolate::New(create_params);
   isolate->Enter();