ADT/Triple: Move a variety of clients to using isOSDarwin() and isOSWindows()
predicates.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129816 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMAsmBackend.cpp b/lib/Target/ARM/ARMAsmBackend.cpp
index e972a08..f062819 100644
--- a/lib/Target/ARM/ARMAsmBackend.cpp
+++ b/lib/Target/ARM/ARMAsmBackend.cpp
@@ -501,18 +501,16 @@
 TargetAsmBackend *llvm::createARMAsmBackend(const Target &T,
                                             const std::string &TT) {
   Triple TheTriple(TT);
-  switch (TheTriple.getOS()) {
-  case Triple::Darwin: {
+
+  if (TheTriple.isOSDarwin()) {
     if (TheTriple.getArchName() == "armv6" ||
         TheTriple.getArchName() == "thumbv6")
       return new DarwinARMAsmBackend(T, object::mach::CSARM_V6);
     return new DarwinARMAsmBackend(T, object::mach::CSARM_V7);
   }
-  case Triple::MinGW32:
-  case Triple::Cygwin:
-  case Triple::Win32:
+
+  if (TheTriple.isOSWindows())
     assert(0 && "Windows not supported on ARM");
-  default:
-    return new ELFARMAsmBackend(T, Triple(TT).getOS());
-  }
+
+  return new ELFARMAsmBackend(T, Triple(TT).getOS());
 }