[libc++] Add custom clang-tidy checks

Reviewed By: #libc, ldionne

Spies: jwakely, beanz, smeenai, cfe-commits, tschuett, avogelsgesang, Mordante, sstefan1, libcxx-commits, ldionne, mgorny, arichardson, miyuki

Differential Revision: https://reviews.llvm.org/D131963

NOKEYCHECK=True
GitOrigin-RevId: 841399a2188aaf244e83e3df7be66885ec905ede
diff --git a/include/valarray b/include/valarray
index 11a273d..5b1f023 100644
--- a/include/valarray
+++ b/include/valarray
@@ -546,7 +546,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return abs(__x);}
+        {return std::abs(__x);}
 };
 
 template <class _Tp>
@@ -555,7 +555,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return acos(__x);}
+        {return std::acos(__x);}
 };
 
 template <class _Tp>
@@ -564,7 +564,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return asin(__x);}
+        {return std::asin(__x);}
 };
 
 template <class _Tp>
@@ -573,7 +573,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return atan(__x);}
+        {return std::atan(__x);}
 };
 
 template <class _Tp>
@@ -582,7 +582,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return atan2(__x, __y);}
+        {return std::atan2(__x, __y);}
 };
 
 template <class _Tp>
@@ -591,7 +591,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return cos(__x);}
+        {return std::cos(__x);}
 };
 
 template <class _Tp>
@@ -600,7 +600,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return cosh(__x);}
+        {return std::cosh(__x);}
 };
 
 template <class _Tp>
@@ -609,7 +609,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return exp(__x);}
+        {return std::exp(__x);}
 };
 
 template <class _Tp>
@@ -618,7 +618,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return log(__x);}
+        {return std::log(__x);}
 };
 
 template <class _Tp>
@@ -627,7 +627,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return log10(__x);}
+        {return std::log10(__x);}
 };
 
 template <class _Tp>
@@ -636,7 +636,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return pow(__x, __y);}
+        {return std::pow(__x, __y);}
 };
 
 template <class _Tp>
@@ -645,7 +645,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return sin(__x);}
+        {return std::sin(__x);}
 };
 
 template <class _Tp>
@@ -654,7 +654,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return sinh(__x);}
+        {return std::sinh(__x);}
 };
 
 template <class _Tp>
@@ -663,7 +663,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return sqrt(__x);}
+        {return std::sqrt(__x);}
 };
 
 template <class _Tp>
@@ -672,7 +672,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return tan(__x);}
+        {return std::tan(__x);}
 };
 
 template <class _Tp>
@@ -681,7 +681,7 @@
     typedef _Tp __result_type;
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
-        {return tanh(__x);}
+        {return std::tanh(__x);}
 };
 
 template <class _ValExpr>