[Driver][cc1][cc1as] Call OptTable::PrintHelp with explicit " [options] file..."

Summary: This is to accommodate a change in llvm/lib/Option/OptTable.cpp D51009

Reviewers: rupprecht, alexshap, jhenderson

Reviewed By: rupprecht

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D51109

llvm-svn: 344098
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index ebf2ffc..203dcbe 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -68,6 +68,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Process.h"
@@ -1433,7 +1434,8 @@
   if (!ShowHidden)
     ExcludedFlagsBitmask |= HelpHidden;
 
-  getOpts().PrintHelp(llvm::outs(), Name.c_str(), DriverTitle.c_str(),
+  std::string Usage = llvm::formatv("{0} [options] file...", Name).str();
+  getOpts().PrintHelp(llvm::outs(), Usage.c_str(), DriverTitle.c_str(),
                       IncludedFlagsBitmask, ExcludedFlagsBitmask,
                       /*ShowAllAliases=*/false);
 }