ARMAsmBackend.cpp: Use Triple::isOSBinFormatCOFF() instead of isOSWindows().

FYI, isOSBinFormatCOFF() is as same as isOSWindows(), on trunk.

llvm-svn: 183727
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index 5ef9314..2488b6b 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -680,7 +680,7 @@
     return new DarwinARMAsmBackend(T, TT, CS);
   }
 
-  if (TheTriple.isOSWindows())
+  if (TheTriple.isOSBinFormatCOFF())
     assert(0 && "Windows not supported on ARM");
 
   uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());