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/Mips.h b/clang/lib/Basic/Targets/Mips.h
index f207809..d49f498 100644
--- a/clang/lib/Basic/Targets/Mips.h
+++ b/clang/lib/Basic/Targets/Mips.h
@@ -78,8 +78,8 @@
 
     CPU = ABI == "o32" ? "mips32r2" : "mips64r2";
 
-    CanUseBSDABICalls = Triple.getOS() == llvm::Triple::FreeBSD ||
-                        Triple.getOS() == llvm::Triple::OpenBSD;
+    CanUseBSDABICalls = Triple.isOSFreeBSD() ||
+                        Triple.isOSOpenBSD();
   }
 
   bool isIEEE754_2008Default() const {
@@ -132,7 +132,7 @@
   void setN32N64ABITypes() {
     LongDoubleWidth = LongDoubleAlign = 128;
     LongDoubleFormat = &llvm::APFloat::IEEEquad();
-    if (getTriple().getOS() == llvm::Triple::FreeBSD) {
+    if (getTriple().isOSFreeBSD()) {
       LongDoubleWidth = LongDoubleAlign = 64;
       LongDoubleFormat = &llvm::APFloat::IEEEdouble();
     }
@@ -142,7 +142,7 @@
 
   void setN64ABITypes() {
     setN32N64ABITypes();
-    if (getTriple().getOS() == llvm::Triple::OpenBSD) {
+    if (getTriple().isOSOpenBSD()) {
       Int64Type = SignedLongLong;
     } else {
       Int64Type = SignedLong;