Use internal storage for command line option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139079 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index fddb7fb..17e5733 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -95,12 +95,10 @@
 //===----------------------------------------------------------------------===//
 // Command line options for x86
 //===----------------------------------------------------------------------===//
-bool UseVZeroUpper;
-
-static cl::opt<bool, true>
-VZeroUpper("x86-use-vzeroupper",
+static cl::opt<bool>
+UseVZeroUpper("x86-use-vzeroupper",
   cl::desc("Minimize AVX to SSE transition penalty"),
-  cl::location(UseVZeroUpper), cl::init(false));
+  cl::init(false));
 
 //===----------------------------------------------------------------------===//
 // Pass Pipeline Configuration