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/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 79d8454..48d798b 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -184,7 +184,7 @@
   unsigned Version[3];
   getTargetVersion(Version);
 
-  llvm::SmallString<16> Str;
+  SmallString<16> Str;
   llvm::raw_svector_ostream(Str)
     << (isTargetIPhoneOS() ? "ios" : "macosx")
     << Version[0] << "." << Version[1] << "." << Version[2];
@@ -1132,7 +1132,7 @@
   SmallVector<std::string, 8> Prefixes(D.PrefixDirs.begin(),
                                        D.PrefixDirs.end());
 
-  llvm::SmallString<128> CxxInstallRoot(GCC_INSTALL_PREFIX);
+  SmallString<128> CxxInstallRoot(GCC_INSTALL_PREFIX);
   if (CxxInstallRoot != "") {
     if (CxxInstallRoot.back() == '/')
       llvm::sys::path::remove_filename(CxxInstallRoot); // remove the /