Revert r351954 "Add a value_type to ArrayRef."

This breaks arm self-hosted buildbots.

llvm-svn: 352206

Author: legrosbuffle

llvm/include/llvm/ADT/ArrayRef.h

@@ -44,7 +44,6 @@ namespace llvm {
     using const_iterator = const T *;
     using size_type = size_t;
     using reverse_iterator = std::reverse_iterator<iterator>;
-    using value_type = typename std::remove_cv<T>::type;
 
   private:
     /// The start of the array, in an external buffer.

llvm/unittests/ADT/ArrayRefTest.cpp

@@ -51,14 +51,6 @@ static_assert(
     "Assigning from an initializer list");
 #endif
 
-// Check Typedefs.
-static_assert(
-    std::is_same<ArrayRef<int>::value_type, int>::value,
-    "erroneous value_type");
-static_assert(
-    std::is_same<ArrayRef<const int>::value_type, int>::value,
-    "erroneous value_type");
-
 namespace {
 
 TEST(ArrayRefTest, AllocatorCopy) {