Add a function to check if an argument list is too long.

This will be used in clang to decide if it should create an @file or not. It
will be tested on the clang side.

Patch by Nathan Froyd.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179285 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/Program.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_SUPPORT_PROGRAM_H
 #define LLVM_SUPPORT_PROGRAM_H
 
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/Path.h"
 
 namespace llvm {
@@ -140,6 +141,10 @@ namespace sys {
     /// @}
 
   };
+
+  // Return true if the given arguments fit within system-specific
+  // argument length limits.
+  bool argumentsFitWithinSystemLimits(ArrayRef<const char*> Args);
 }
 }