Fix __gnu_cxx::_Pointer_adapter for long long arithmetic

	* include/ext/pointer.h (_Pointer_adapter): Define operators for
	pointer arithmetic using long long offsets.
	* testsuite/ext/ext_pointer/1.cc: Test pointer arithmetic using
	long long values.

From-SVN: r263976

libstdc++-v3/ChangeLog

+2018-08-30  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/ext/pointer.h (_Pointer_adapter): Define operators for
+	pointer arithmetic using long long offsets.
+	* testsuite/ext/ext_pointer/1.cc: Test pointer arithmetic using
+	long long values.
+
 2018-08-29  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/31413

libstdc++-v3/include/ext/pointer.h

@@ -441,6 +441,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _CXX_POINTER_ARITH_OPERATOR_SET(unsigned int);
       _CXX_POINTER_ARITH_OPERATOR_SET(long);
       _CXX_POINTER_ARITH_OPERATOR_SET(unsigned long);
+#ifdef _GLIBCXX_USE_LONG_LONG
+      _CXX_POINTER_ARITH_OPERATOR_SET(long long);
+      _CXX_POINTER_ARITH_OPERATOR_SET(unsigned long long);
+#endif
 
       // Mathematical Manipulators
       inline _Pointer_adapter& 

libstdc++-v3/testsuite/ext/ext_pointer/1.cc

@@ -180,11 +180,25 @@ void test04() {
   VERIFY(bPtr3 == aPtr);
 }
 
+// Check that long long values can be used for pointer arithmetic.
+void test05()
+{
+  A a[2] = { 1, 2 };
+  A_pointer p = a;
+  A_pointer q = p + 0ull;
+  VERIFY( p == q );
+  q += 0ll;
+  VERIFY( p == q );
+  q += 1ll;
+  VERIFY( q->i == p[1ll].i );
+}
+
 int main()
 {
   test01();
   test02();
   test03();
   test04();
+  test05();
   return 0;
 }