Add NetBSD support

NetBSD is a modern UNIX-like Operating System.

Enable GTEST_HAS_PTHREAD and GTEST_HAS_DEATH_TEST on NetBSD.

googletest/include/gtest/internal/gtest-port-arch.h

@@ -84,6 +84,8 @@
 # define GTEST_OS_HPUX 1
 #elif defined __native_client__
 # define GTEST_OS_NACL 1
+#elif defined __NetBSD__
+# define GTEST_OS_NETBSD 1
 #elif defined __OpenBSD__
 # define GTEST_OS_OPENBSD 1
 #elif defined __QNX__

googletest/include/gtest/internal/gtest-port.h

@@ -128,6 +128,7 @@
 //   GTEST_OS_MAC      - Mac OS X
 //     GTEST_OS_IOS    - iOS
 //   GTEST_OS_NACL     - Google Native Client (NaCl)
+//   GTEST_OS_NETBSD   - NetBSD
 //   GTEST_OS_OPENBSD  - OpenBSD
 //   GTEST_OS_QNX      - QNX
 //   GTEST_OS_SOLARIS  - Sun Solaris
@@ -607,7 +608,7 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
 // To disable threading support in Google Test, add -DGTEST_HAS_PTHREAD=0
 // to your compiler flags.
 # define GTEST_HAS_PTHREAD (GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_HPUX \
-    || GTEST_OS_QNX || GTEST_OS_FREEBSD || GTEST_OS_NACL)
+    || GTEST_OS_QNX || GTEST_OS_FREEBSD || GTEST_OS_NACL || GTEST_OS_NETBSD)
 #endif  // GTEST_HAS_PTHREAD
 
 #if GTEST_HAS_PTHREAD
@@ -800,7 +801,7 @@ using ::std::tuple_size;
      (GTEST_OS_MAC && !GTEST_OS_IOS) || \
      (GTEST_OS_WINDOWS_DESKTOP && _MSC_VER >= 1400) || \
      GTEST_OS_WINDOWS_MINGW || GTEST_OS_AIX || GTEST_OS_HPUX || \
-     GTEST_OS_OPENBSD || GTEST_OS_QNX || GTEST_OS_FREEBSD)
+     GTEST_OS_OPENBSD || GTEST_OS_QNX || GTEST_OS_FREEBSD || GTEST_OS_NETBSD)
 # define GTEST_HAS_DEATH_TEST 1
 #endif