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/VirtualCallChecker.cpp b/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
index 4b3c427..f769ea6 100644
--- a/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
@@ -160,7 +160,7 @@
 }
 
 void WalkAST::ReportVirtualCall(const CallExpr *CE, bool isPure) {
-  llvm::SmallString<100> buf;
+  SmallString<100> buf;
   llvm::raw_svector_ostream os(buf);
   
   os << "Call Path : ";