Rebased localmods in libcxx to 223109.

include/cmath

Index: include/cmath
diff --git a/include/cmath b/include/cmath
index d3aa4beeb584f9a54ea0c98201e174e101c2853a..bddae84a88a150e301470aa54a2afab6d731575d 100644
--- a/include/cmath
+++ b/include/cmath
@@ -1377,7 +1377,11 @@ using ::log2;
 using ::log2f;
 
 inline _LIBCPP_INLINE_VISIBILITY float       log2(float __lcpp_x) _NOEXCEPT       {return log2f(__lcpp_x);}
+#if defined(_NEWLIB_VERSION) // @LOCALMOD-START Missing from newlib. Note that PNaCl represents ``long double`` as ``double``, hence the intrinsic's type.
+inline _LIBCPP_INLINE_VISIBILITY long double log2(long double __lcpp_x) _NOEXCEPT {return __builtin_log2(__lcpp_x);}
+#else
 inline _LIBCPP_INLINE_VISIBILITY long double log2(long double __lcpp_x) _NOEXCEPT {return log2l(__lcpp_x);}
+#endif // @LOCALMOD-END
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
@@ -1390,7 +1394,11 @@ using ::logb;
 using ::logbf;
 
 inline _LIBCPP_INLINE_VISIBILITY float       logb(float __lcpp_x) _NOEXCEPT       {return logbf(__lcpp_x);}
+#if defined(_NEWLIB_VERSION) // @LOCALMOD-START Missing from newlib. Note that PNaCl represents ``long double`` as ``double``, hence the intrinsic's type.
+inline _LIBCPP_INLINE_VISIBILITY long double logb(long double __lcpp_x) _NOEXCEPT {return __builtin_logb(__lcpp_x);}
+#else
 inline _LIBCPP_INLINE_VISIBILITY long double logb(long double __lcpp_x) _NOEXCEPT {return logbl(__lcpp_x);}
+#endif // @LOCALMOD-END
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
@@ -1475,6 +1483,15 @@ nextafter(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
 
 // nexttoward
 
+#if defined(_NEWLIB_VERSION) // @LOCALMOD-START Missing from newlib. Note that PNaCl represents ``long double`` as ``double``, hence the intrinsic's type.
+inline _LIBCPP_INLINE_VISIBILITY float       nexttoward(float __lcpp_x, long double __lcpp_y) _NOEXCEPT       {return __builtin_nexttoward(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double nexttoward(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return __builtin_nexttoward(__lcpp_x, __lcpp_y);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+nexttoward(_A1 __lcpp_x, long double __lcpp_y) _NOEXCEPT {return __builtin_nexttoward((double)__lcpp_x, __lcpp_y);}
+#else
 using ::nexttoward;
 using ::nexttowardf;
 
@@ -1485,7 +1502,7 @@ template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename enable_if<is_integral<_A1>::value, double>::type
 nexttoward(_A1 __lcpp_x, long double __lcpp_y) _NOEXCEPT {return nexttoward((double)__lcpp_x, __lcpp_y);}
-
+#endif // @LOCALMOD-END
 // remainder
 
 using ::remainder;
@@ -1658,14 +1675,18 @@ using ::lgammal;
 using ::llrintl;
 using ::llroundl;
 using ::log1pl;
+#if !defined(_NEWLIB_VERSION) // @LOCALMOD-START Missing from newlib.
 using ::log2l;
 using ::logbl;
+#endif // @LOCALMOD-END
 using ::lrintl;
 using ::lroundl;
 using ::nanl;
 using ::nearbyintl;
 using ::nextafterl;
+#if !defined(_NEWLIB_VERSION) // @LOCALMOD-START Missing from newlib.
 using ::nexttowardl;
+#endif // @LOCALMOD-END
 using ::remainderl;
 using ::remquol;
 using ::rintl;