Move using directive from Job.h to Job.cpp

I don't think it belongs in the header, but seems handy in the .cpp file.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190902 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Job.cpp b/lib/Driver/Job.cpp
index 0a783eb..43518ad 100644
--- a/lib/Driver/Job.cpp
+++ b/lib/Driver/Job.cpp
@@ -15,14 +15,14 @@
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 using namespace clang::driver;
+using llvm::opt::ArgStringList;
 using llvm::raw_ostream;
 using llvm::StringRef;
 
 Job::~Job() {}
 
 Command::Command(const Action &_Source, const Tool &_Creator,
-                 const char *_Executable,
-                 const llvm::opt::ArgStringList &_Arguments)
+                 const char *_Executable, const ArgStringList &_Arguments)
     : Job(CommandClass), Source(_Source), Creator(_Creator),
       Executable(_Executable), Arguments(_Arguments) {}
 
@@ -113,7 +113,7 @@
   OS << Terminator;
 }
 
-int Command::Execute(const llvm::StringRef **Redirects, std::string *ErrMsg,
+int Command::Execute(const StringRef **Redirects, std::string *ErrMsg,
                      bool *ExecutionFailed) const {
   SmallVector<const char*, 128> Argv;
   Argv.push_back(Executable);