Fix a couple of unguarded operator, calls in algorithm. Fixes PR#43063. Updated all the heap tests to check this.

llvm-svn: 369448
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 91cca5c..b90f33c 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -3117,10 +3117,10 @@
                          input_iterator_tag) {
 
   _Distance __k = 0;
-  for (; __first != __last && __k < __n; ++__first, (void)++__k)
+  for (; __first != __last && __k < __n; ++__first, (void) ++__k)
     __output_iter[__k] = *__first;
   _Distance __sz = __k;
-  for (; __first != __last; ++__first, (void)++__k) {
+  for (; __first != __last; ++__first, (void) ++__k) {
     _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
     if (__r < __sz)
       __output_iter[__r] = *__first;
@@ -3190,7 +3190,7 @@
     if (__d > 1)
     {
         _Dp __uid;
-        for (--__last, --__d; __first < __last; ++__first, --__d)
+        for (--__last, (void) --__d; __first < __last; ++__first, (void) --__d)
         {
             difference_type __i = __uid(__g, _Pp(0, __d));
             if (__i != difference_type(0))
@@ -3373,7 +3373,7 @@
         // All trues now at start of range, all falses in buffer
         // Move falses back into range, but don't mess up __first which points to first false
         __i = __first;
-        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
+        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
             *__i = _VSTD::move(*__t2);
         // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
         return __first;
@@ -3505,7 +3505,7 @@
         __i = ++__first;
         // All trues now at start of range, all falses in buffer
         // Move falses back into range, but don't mess up __first which points to first false
-        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
+        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
             *__i = _VSTD::move(*__t2);
         // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
         return __first;
@@ -4428,14 +4428,14 @@
     if (__len1 <= __len2)
     {
         value_type* __p = __buff;
-        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, ++__p)
+        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, (void) ++__p)
             ::new(__p) value_type(_VSTD::move(*__i));
         __half_inplace_merge(__buff, __p, __middle, __last, __first, __comp);
     }
     else
     {
         value_type* __p = __buff;
-        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, ++__p)
+        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, (void) ++__p)
             ::new(__p) value_type(_VSTD::move(*__i));
         typedef reverse_iterator<_BidirectionalIterator> _RBi;
         typedef reverse_iterator<value_type*> _Rv;
@@ -4575,14 +4575,14 @@
     {
         if (__first1 == __last1)
         {
-            for (; __first2 != __last2; ++__first2, ++__result, __d.__incr((value_type*)0))
+            for (; __first2 != __last2; ++__first2, ++__result, (void) __d.__incr((value_type*)0))
                 ::new (__result) value_type(_VSTD::move(*__first2));
             __h.release();
             return;
         }
         if (__first2 == __last2)
         {
-            for (; __first1 != __last1; ++__first1, ++__result, __d.__incr((value_type*)0))
+            for (; __first1 != __last1; ++__first1, ++__result, (void) __d.__incr((value_type*)0))
                 ::new (__result) value_type(_VSTD::move(*__first1));
             __h.release();
             return;
@@ -4612,7 +4612,7 @@
     {
         if (__first2 == __last2)
         {
-            for (; __first1 != __last1; ++__first1, ++__result)
+            for (; __first1 != __last1; ++__first1, (void) ++__result)
                 *__result = _VSTD::move(*__first1);
             return;
         }
@@ -4627,7 +4627,7 @@
             ++__first1;
         }
     }
-    for (; __first2 != __last2; ++__first2, ++__result)
+    for (; __first2 != __last2; ++__first2, (void) ++__result)
         *__result = _VSTD::move(*__first2);
 }
 
@@ -4995,7 +4995,7 @@
 __sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
 {
     typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    for (difference_type __n = __last - __first; __n > 1; --__last, --__n)
+    for (difference_type __n = __last - __first; __n > 1; --__last, (void) --__n)
         __pop_heap<_Compare>(__first, __last, __comp, __n);
 }
 
@@ -5065,7 +5065,7 @@
     _RandomAccessIterator __r = __result_first;
     if (__r != __result_last)
     {
-        for (; __first != __last && __r != __result_last; (void) ++__first, ++__r)
+        for (; __first != __last && __r != __result_last; ++__first, (void) ++__r)
             *__r = *__first;
         __make_heap<_Compare>(__result_first, __r, __comp);
         typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;