diff --git a/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
index bf30a8e6663..78403424da6 100644
--- a/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -717,11 +717,10 @@ public:
 };
 
 class DarwinX86_32AsmBackend : public DarwinX86AsmBackend {
-  bool SupportsCU;
 public:
   DarwinX86_32AsmBackend(const Target &T, const MCRegisterInfo &MRI,
-                         StringRef CPU, bool SupportsCU)
-    : DarwinX86AsmBackend(T, MRI, CPU, false), SupportsCU(SupportsCU) {}
+                         StringRef CPU)
+      : DarwinX86AsmBackend(T, MRI, CPU, false) {}
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const override {
     return createX86MachObjectWriter(OS, /*Is64Bit=*/false,
@@ -732,20 +731,16 @@ public:
   /// \brief Generate the compact unwind encoding for the CFI instructions.
   uint32_t generateCompactUnwindEncoding(
                              ArrayRef<MCCFIInstruction> Instrs) const override {
-    return SupportsCU ? generateCompactUnwindEncodingImpl(Instrs) : 0;
+    return generateCompactUnwindEncodingImpl(Instrs);
   }
 };
 
 class DarwinX86_64AsmBackend : public DarwinX86AsmBackend {
-  bool SupportsCU;
   const MachO::CPUSubTypeX86 Subtype;
 public:
   DarwinX86_64AsmBackend(const Target &T, const MCRegisterInfo &MRI,
-                         StringRef CPU, bool SupportsCU,
-                         MachO::CPUSubTypeX86 st)
-    : DarwinX86AsmBackend(T, MRI, CPU, true), SupportsCU(SupportsCU),
-      Subtype(st) {
-  }
+                         StringRef CPU, MachO::CPUSubTypeX86 st)
+      : DarwinX86AsmBackend(T, MRI, CPU, true), Subtype(st) {}
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const override {
     return createX86MachObjectWriter(OS, /*Is64Bit=*/true,
@@ -788,7 +783,7 @@ public:
   /// \brief Generate the compact unwind encoding for the CFI instructions.
   uint32_t generateCompactUnwindEncoding(
                              ArrayRef<MCCFIInstruction> Instrs) const override {
-    return SupportsCU ? generateCompactUnwindEncodingImpl(Instrs) : 0;
+    return generateCompactUnwindEncodingImpl(Instrs);
   }
 };
 
@@ -801,9 +796,7 @@ MCAsmBackend *llvm::createX86_32AsmBackend(const Target &T,
   Triple TheTriple(TT);
 
   if (TheTriple.isOSBinFormatMachO())
-    return new DarwinX86_32AsmBackend(T, MRI, CPU,
-                                      TheTriple.isMacOSX() &&
-                                      !TheTriple.isMacOSXVersionLT(10, 7));
+    return new DarwinX86_32AsmBackend(T, MRI, CPU);
 
   if (TheTriple.isOSWindows() && !TheTriple.isOSBinFormatELF())
     return new WindowsX86AsmBackend(T, false, CPU);
@@ -823,9 +816,7 @@ MCAsmBackend *llvm::createX86_64AsmBackend(const Target &T,
         StringSwitch<MachO::CPUSubTypeX86>(TheTriple.getArchName())
             .Case("x86_64h", MachO::CPU_SUBTYPE_X86_64_H)
             .Default(MachO::CPU_SUBTYPE_X86_64_ALL);
-    return new DarwinX86_64AsmBackend(T, MRI, CPU,
-                                      TheTriple.isMacOSX() &&
-                                      !TheTriple.isMacOSXVersionLT(10, 7), CS);
+    return new DarwinX86_64AsmBackend(T, MRI, CPU, CS);
   }
 
   if (TheTriple.isOSWindows() && !TheTriple.isOSBinFormatELF())