[libcxx] [test] Rename __x to x. NFCI.

This improves readability and (theoretically) improves portability,
as __ugly names are reserved.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@310760 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/std/numerics/numeric.ops/transform.exclusive.scan/transform_exclusive_scan_init_bop_uop.pass.cpp b/test/std/numerics/numeric.ops/transform.exclusive.scan/transform_exclusive_scan_init_bop_uop.pass.cpp
index 2226ac7..4964e8e 100644
--- a/test/std/numerics/numeric.ops/transform.exclusive.scan/transform_exclusive_scan_init_bop_uop.pass.cpp
+++ b/test/std/numerics/numeric.ops/transform.exclusive.scan/transform_exclusive_scan_init_bop_uop.pass.cpp
@@ -28,17 +28,17 @@
 template <class T = void>
 struct identity : std::unary_function<T, T>
 {
-    constexpr const T& operator()(const T& __x) const { return __x;}
+    constexpr const T& operator()(const T& x) const { return x;}
 };
 
 template <>
 struct identity<void>
 {
     template <class T>
-    constexpr auto operator()(T&& __x) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<T>(__x)))
-    -> decltype        (_VSTD::forward<T>(__x))
-        { return        _VSTD::forward<T>(__x); }
+    constexpr auto operator()(T&& x) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<T>(x)))
+    -> decltype        (_VSTD::forward<T>(x))
+        { return        _VSTD::forward<T>(x); }
 };
 
 template <class Iter1, class BOp, class UOp, class T, class Iter2>
diff --git a/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop.pass.cpp b/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop.pass.cpp
index 246467b..d15defc 100644
--- a/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop.pass.cpp
+++ b/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop.pass.cpp
@@ -1,3 +1,4 @@
+
 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
@@ -28,17 +29,17 @@
 template <class T = void>
 struct identity : std::unary_function<T, T>
 {
-    constexpr const T& operator()(const T& __x) const { return __x;}
+    constexpr const T& operator()(const T& x) const { return x;}
 };
 
 template <>
 struct identity<void>
 {
     template <class T>
-    constexpr auto operator()(T&& __x) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<T>(__x)))
-    -> decltype        (_VSTD::forward<T>(__x))
-        { return        _VSTD::forward<T>(__x); }
+    constexpr auto operator()(T&& x) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<T>(x)))
+    -> decltype        (_VSTD::forward<T>(x))
+        { return        _VSTD::forward<T>(x); }
 };
 
 template <class Iter1, class BOp, class UOp, class Iter2>
diff --git a/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop_init.pass.cpp b/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop_init.pass.cpp
index 453e036..b38b9a5 100644
--- a/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop_init.pass.cpp
+++ b/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop_init.pass.cpp
@@ -28,17 +28,17 @@
 template <class T = void>
 struct identity : std::unary_function<T, T>
 {
-    constexpr const T& operator()(const T& __x) const { return __x;}
+    constexpr const T& operator()(const T& x) const { return x;}
 };
 
 template <>
 struct identity<void>
 {
     template <class T>
-    constexpr auto operator()(T&& __x) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<T>(__x)))
-    -> decltype        (_VSTD::forward<T>(__x))
-        { return        _VSTD::forward<T>(__x); }
+    constexpr auto operator()(T&& x) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<T>(x)))
+    -> decltype        (_VSTD::forward<T>(x))
+        { return        _VSTD::forward<T>(x); }
 };
 
 template <class Iter1, class BOp, class UOp, class T, class Iter2>
diff --git a/test/std/numerics/numeric.ops/transform.reduce/transform_reduce_iter_iter_init_bop_uop.pass.cpp b/test/std/numerics/numeric.ops/transform.reduce/transform_reduce_iter_iter_init_bop_uop.pass.cpp
index b648aa5..418c57f 100644
--- a/test/std/numerics/numeric.ops/transform.reduce/transform_reduce_iter_iter_init_bop_uop.pass.cpp
+++ b/test/std/numerics/numeric.ops/transform.reduce/transform_reduce_iter_iter_init_bop_uop.pass.cpp
@@ -24,34 +24,34 @@
 template <class T = void>
 struct identity : std::unary_function<T, T>
 {
-    constexpr const T& operator()(const T& __x) const { return __x;}
+    constexpr const T& operator()(const T& x) const { return x;}
 };
 
 template <>
 struct identity<void>
 {
     template <class T>
-    constexpr auto operator()(T&& __x) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<T>(__x)))
-    -> decltype        (_VSTD::forward<T>(__x))
-        { return        _VSTD::forward<T>(__x); }
+    constexpr auto operator()(T&& x) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<T>(x)))
+    -> decltype        (_VSTD::forward<T>(x))
+        { return        _VSTD::forward<T>(x); }
 };
 
 
 template <class T = void>
 struct twice
 {
-    constexpr const T operator()(const T& __x) const noexcept { return 2 * __x; }
+    constexpr const T operator()(const T& x) const noexcept { return 2 * x; }
 };
 
 template <>
 struct twice<void>
 {
     template <class T>
-    constexpr auto operator()(const T& __x) const
-    _NOEXCEPT_(noexcept(2 * __x))
-    -> decltype        (2 * __x)
-        { return        2 * __x; }
+    constexpr auto operator()(const T& x) const
+    _NOEXCEPT_(noexcept(2 * x))
+    -> decltype        (2 * x)
+        { return        2 * x; }
 };
 
 template <class Iter1, class T, class BOp, class UOp>