[MC/Mach-O] Add AsmParser support for .linker_option directive.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172778 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCStreamer.h

@@ -20,6 +20,7 @@
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/MCWin64EH.h"
 #include "llvm/Support/DataTypes.h"
+#include <string>
 
 namespace llvm {
   class MCAsmBackend;
@@ -255,6 +256,10 @@ namespace llvm {
     /// EmitAssemblerFlag - Note in the output the specified @p Flag.
     virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
 
+    /// EmitLinkerOptions - Emit the given list @p Options of strings as linker
+    /// options into the output.
+    virtual void EmitLinkerOptions(ArrayRef<std::string> Kind) {}
+
     /// EmitDataRegion - Note in the output the specified region @p Kind.
     virtual void EmitDataRegion(MCDataRegionType Kind) {}