Remove -disable-red-zone command line option from LLC.

[srking]

Summary

This patch removes the -disable-red-zone command line option from LLC.
Discussion for rejected patch D5681 concluded that function attributes should be the single way to disable the red-zone. As such, the clang command line already controls this feature.

[• rafael]

LGTM!

[Eugene.Zelenko]

Committed in rL221282.

include/llvm/CodeGen/CommandFlags.h

cl::values(
                         "Emit an assembly ('.s') file"),
              clEnumValN(TargetMachine::CGFT_ObjectFile, "obj",
                         "Emit a native object ('.o') file"),
              clEnumValN(TargetMachine::CGFT_Null, "null",
                         "Emit nothing, for performance testing"),
              clEnumValEnd));
 
 cl::opt<bool>
-DisableRedZone("disable-red-zone",
-               cl::desc("Do not emit code that uses the red zone."),
-               cl::init(false));
-
-cl::opt<bool>
 EnableFPMAD("enable-fp-mad",
             cl::desc("Enable less precise MAD instructions to be generated"),
             cl::init(false));
 
 cl::opt<bool>
 DisableFPElim("disable-fp-elim",
               cl::desc("Disable frame pointer elimination optimization"),
               cl::init(false));