Replace getOS() == llvm::Triple::*BSD with isOS*BSD() [NFCI]

Replace multiple comparisons of getOS() value with FreeBSD, NetBSD,
OpenBSD and DragonFly with matching isOS*BSD() methods.  This should
improve the consistency of coding style without changing the behavior.
Direct getOS() comparisons were left whenever used in switch or switch-
like context.

Differential Revision: https://reviews.llvm.org/D55916

llvm-svn: 349752
diff --git a/clang/lib/Basic/Targets/PPC.cpp b/clang/lib/Basic/Targets/PPC.cpp
index db54fcf..6cfbed1 100644
--- a/clang/lib/Basic/Targets/PPC.cpp
+++ b/clang/lib/Basic/Targets/PPC.cpp
@@ -83,8 +83,8 @@
   if (getTriple().getArch() == llvm::Triple::ppc64le) {
     Builder.defineMacro("_LITTLE_ENDIAN");
   } else {
-    if (getTriple().getOS() != llvm::Triple::NetBSD &&
-        getTriple().getOS() != llvm::Triple::OpenBSD)
+    if (!getTriple().isOSNetBSD() &&
+        !getTriple().isOSOpenBSD())
       Builder.defineMacro("_BIG_ENDIAN");
   }