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/Frontend/VerifyDiagnosticConsumer.cpp b/lib/Frontend/VerifyDiagnosticConsumer.cpp
index c8d6be6..67bc5ef 100644
--- a/lib/Frontend/VerifyDiagnosticConsumer.cpp
+++ b/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -378,7 +378,7 @@
                              const char *Kind, bool Expected) {
   if (diag_begin == diag_end) return 0;
 
-  llvm::SmallString<256> Fmt;
+  SmallString<256> Fmt;
   llvm::raw_svector_ostream OS(Fmt);
   for (const_diag_iterator I = diag_begin, E = diag_end; I != E; ++I) {
     if (I->first.isInvalid() || !SourceMgr)
@@ -399,7 +399,7 @@
   if (DL.empty())
     return 0;
 
-  llvm::SmallString<256> Fmt;
+  SmallString<256> Fmt;
   llvm::raw_svector_ostream OS(Fmt);
   for (DirectiveList::iterator I = DL.begin(), E = DL.end(); I != E; ++I) {
     Directive& D = **I;