[PATCH] [libcxx] Partially address a FIXME in steady_clock::now()

[Dan Albert]

================
Comment at: include/__config:644
@@ +643,3 @@
+    (defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK > 0)
+#define _LIBCPP_HAS_MONOTONIC_CLOCK 1
+#endif
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As mentioned on http://reviews.llvm.org/D3969, _LIBCPP_HAS_NO_MONOTONIC_CLOCK will more closely match the other configs.

http://reviews.llvm.org/D4045