PPC: fix allocation issues for PPC64.

src/snapshot-common.cc

Index: src/snapshot-common.cc
diff --git a/src/snapshot-common.cc b/src/snapshot-common.cc
index 6bcabffb8111121b2360fd388c377034acab5099..a3e80185702622a48dabb1b8a2ef9130757bf2c5 100644
--- a/src/snapshot-common.cc
+++ b/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);