Tweak a couple of tests on win32 hosts with +Asserts.

  - Don't use assert(0), or tests may pass or fail according to assertions.
  - For now, The tests are marked as XFAIL for win32 hosts.

FIXME: Could we avoid XFAIL to specify triple in the RUN lines?
llvm-svn: 183728
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index 2488b6b..1f0f9eb 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -681,7 +681,7 @@
   }
 
   if (TheTriple.isOSBinFormatCOFF())
-    assert(0 && "Windows not supported on ARM");
+    llvm_unreachable("Windows not supported on ARM");
 
   uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());
   return new ELFARMAsmBackend(T, TT, OSABI);