Basic: import SmallString<> into clang namespace

(I was going to fix the TODO about DenseMap too, but
that would break self-host right now. See PR11922.)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149799 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp b/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
index 2d49027..c6efe94 100644
--- a/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
+++ b/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
@@ -193,7 +193,7 @@
   // FIXME: This diagnostics are preliminary.  We should get far better
   // diagnostics for explaining buffer overruns.
 
-  llvm::SmallString<256> buf;
+  SmallString<256> buf;
   llvm::raw_svector_ostream os(buf);
   os << "Out of bound memory access ";
   switch (kind) {