[Triple] Define OS Check for Haiku

This adds the OS check for the Haiku operating system, as it was
missing in the Triple class. Tests for x86_64-unknown-haiku and
i586-pc-haiku were also added.

These patches only affect Haiku and are completely harmless for
other platforms.

Patch by Calvin Hill <calvin@hakobaito.co.uk>

llvm-svn: 311153
diff --git a/llvm/include/llvm/ADT/Triple.h b/llvm/include/llvm/ADT/Triple.h
index c6e87de..a4cdeb8 100644
--- a/llvm/include/llvm/ADT/Triple.h
+++ b/llvm/include/llvm/ADT/Triple.h
@@ -504,6 +504,11 @@
     return getOS() == Triple::Contiki;
   }
 
+  /// Tests whether the OS is Haiku.
+  bool isOSHaiku() const {
+    return getOS() == Triple::Haiku;
+  }
+
   /// Checks if the environment could be MSVC.
   bool isWindowsMSVCEnvironment() const {
     return getOS() == Triple::Win32 &&
diff --git a/llvm/unittests/ADT/TripleTest.cpp b/llvm/unittests/ADT/TripleTest.cpp
index 16732c9..c16a332 100644
--- a/llvm/unittests/ADT/TripleTest.cpp
+++ b/llvm/unittests/ADT/TripleTest.cpp
@@ -296,6 +296,18 @@
   EXPECT_EQ(Triple::Linux, T.getOS());
   EXPECT_EQ(Triple::GNUEABI, T.getEnvironment());
 
+  T = Triple("i586-pc-haiku");
+  EXPECT_EQ(Triple::x86, T.getArch());
+  EXPECT_EQ(Triple::PC, T.getVendor());
+  EXPECT_EQ(Triple::Haiku, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
+  T = Triple("x86_64-unknown-haiku");
+  EXPECT_EQ(Triple::x86_64, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::Haiku, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
   T = Triple("huh");
   EXPECT_EQ(Triple::UnknownArch, T.getArch());
 }