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/UndefCapturedBlockVarChecker.cpp b/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
index 0be5cf1..8a46035 100644
--- a/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
@@ -84,7 +84,7 @@
           BT.reset(new BuiltinBug("uninitialized variable captured by block"));
 
         // Generate a bug report.
-        llvm::SmallString<128> buf;
+        SmallString<128> buf;
         llvm::raw_svector_ostream os(buf);
 
         os << "Variable '" << VD->getName()