Hide -global-merge option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138540 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index 39552ac..78a6a43 100644
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -22,7 +22,7 @@
 using namespace llvm;
 
 static cl::opt<bool>
-EnableGlobalMerge("global-merge",
+EnableGlobalMerge("global-merge", cl::Hidden,
                   cl::desc("Enable global merge pass"),
                   cl::init(true));