[googletest] Add workaround to fix the build on Debian 8. (gcc-4.9)

gcc-4.9 doesn't support std::is_trivially_copy_constructible<T> or
std::is_trivially_destructible<T>, so use __has_trivial_copy(T)
and __has_trivial_destructor(T) on old gcc.

It's not a perfect fix, but it gets the code to compile.

(I'm using Debian 8 to test big-endian using qemu-system-ppc.
Surprisingly, it's faster than Wii U Linux, even with all of
the CPU emulation overhead!)

extlib/googletest/_MODIFIED_GTEST.txt

@@ -27,5 +27,9 @@ The following changes have been made to the original:
 - Removed test suites, scripts, and Xcode projects in order to reduce
   warnings on LGTM.
 
+- Add a workaround for std::is_trivially_copy_constructible<T> and
+  std::is_trivially_destructible<T> not being implemented in gcc-4.9.
+  (They were added in gcc-5.) Fixes the build on Debian 8.
+
 To obtain the original googletest-1.12.1, visit:
 https://github.com/google/googletest

extlib/googletest/googletest/include/gtest/gtest-matchers.h

@@ -428,11 +428,22 @@ class MatcherBase : private MatcherDescriberInterface {
     }
   }
 
+// rom-properties: Fix build with Debian 8. (gcc-4.9)
+// https://stackoverflow.com/questions/25123458/is-trivially-copyable-is-not-a-member-of-std
+// https://stackoverflow.com/a/31798726
+#if defined(__GNUG__) && __GNUC__ < 5
+#  define IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)  __has_trivial_copy(T)
+#  define IS_TRIVIALLY_DESTRUCTIBLE(T)        __has_trivial_destructor(T)
+#else
+#  define IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)  std::is_trivially_copy_constructible<T>::value
+#  define IS_TRIVIALLY_DESTRUCTIBLE(T)        std::is_trivially_destructible<T>::value
+#endif
+
   template <typename M>
   static constexpr bool IsInlined() {
     return sizeof(M) <= sizeof(Buffer) && alignof(M) <= alignof(Buffer) &&
-           std::is_trivially_copy_constructible<M>::value &&
-           std::is_trivially_destructible<M>::value;
+           IS_TRIVIALLY_COPY_CONSTRUCTIBLE(M) &&
+           IS_TRIVIALLY_DESTRUCTIBLE(M);
   }
 
   template <typename M, bool = MatcherBase::IsInlined<M>()>