MC/Mach-O: Stub out explicit MCMachObjectTargetWriter interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121973 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86AsmBackend.cpp b/lib/Target/X86/X86AsmBackend.cpp
index e1c8cb7..3c1c459 100644
--- a/lib/Target/X86/X86AsmBackend.cpp
+++ b/lib/Target/X86/X86AsmBackend.cpp
@@ -46,6 +46,9 @@
 }
 
 namespace {
+class X86MachObjectWriter : public MCMachObjectTargetWriter {
+};
+
 class X86AsmBackend : public TargetAsmBackend {
 public:
   X86AsmBackend(const Target &T)
@@ -362,7 +365,8 @@
     : DarwinX86AsmBackend(T) {}
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
-    return createMachObjectWriter(OS, /*Is64Bit=*/false,
+    return createMachObjectWriter(new X86MachObjectWriter,
+                                  OS, /*Is64Bit=*/false,
                                   object::mach::CTM_i386,
                                   object::mach::CSX86_ALL,
                                   /*IsLittleEndian=*/true);
@@ -377,7 +381,8 @@
   }
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
-    return createMachObjectWriter(OS, /*Is64Bit=*/true,
+    return createMachObjectWriter(new X86MachObjectWriter,
+                                  OS, /*Is64Bit=*/true,
                                   object::mach::CTM_x86_64,
                                   object::mach::CSX86_ALL,
                                   /*IsLittleEndian=*/true);