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/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index a8bfbcd..4efcee2 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -468,7 +468,7 @@
     if (!BT_BadFree)
       BT_BadFree.reset(new BuiltinBug("Bad free"));
     
-    llvm::SmallString<100> buf;
+    SmallString<100> buf;
     llvm::raw_svector_ostream os(buf);
     
     const MemRegion *MR = ArgVal.getAsRegion();