Sink some triple predicates into swiftBasic.

getPlatformNameForTriple isn't currently being used anywhere elsee, but
this seems more consistent.

No functionality change.

Swift SVN r17002

lib/Basic/Platform.cpp

@@ -0,0 +1,35 @@
+//===-- Platform.cpp - Implement platform-related helpers -------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/Basic/Platform.h"
+#include "llvm/ADT/Triple.h"
+
+using namespace swift;
+
+bool swift::tripleIsiOSSimulator(const llvm::Triple &triple) {
+  llvm::Triple::ArchType arch = triple.getArch();
+  return (triple.isiOS() &&
+          (arch == llvm::Triple::x86 || arch == llvm::Triple::x86_64));
+}
+
+StringRef swift::getPlatformNameForTriple(const llvm::Triple &triple) {
+  if (triple.isiOS()) {
+    if (tripleIsiOSSimulator(triple))
+      return "iphonesimulator";
+    return "iphoneos";
+  }
+
+  if (triple.isMacOSX())
+    return "macosx";
+
+  return "";
+}