Minor tweaking to SmallVector static size.

llvm-svn: 169176
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 2ea9cbd..dec28f4 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -709,7 +709,7 @@
 
   // Write metadata kinds
   // METADATA_KIND - [n x [id, name]]
-  SmallVector<StringRef, 4> Names;
+  SmallVector<StringRef, 8> Names;
   M->getMDKindNames(Names);
 
   if (Names.empty()) return;