[libc++][NFC] Make size of allocation more self-documenting

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@358588 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/src/debug.cpp b/src/debug.cpp
index 0f75d8c..93fa1a8 100644
--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -171,7 +171,7 @@
     if (__csz_ + 1 > static_cast<size_t>(__cend_ - __cbeg_))
     {
         size_t nc = __next_prime(2*static_cast<size_t>(__cend_ - __cbeg_) + 1);
-        __c_node** cbeg = static_cast<__c_node**>(calloc(nc, sizeof(void*)));
+        __c_node** cbeg = static_cast<__c_node**>(calloc(nc, sizeof(__c_node*)));
         if (cbeg == nullptr)
             __throw_bad_alloc();
 
@@ -508,7 +508,7 @@
     if (__isz_ + 1 > static_cast<size_t>(__iend_ - __ibeg_))
     {
         size_t nc = __next_prime(2*static_cast<size_t>(__iend_ - __ibeg_) + 1);
-        __i_node** ibeg = static_cast<__i_node**>(calloc(nc, sizeof(void*)));
+        __i_node** ibeg = static_cast<__i_node**>(calloc(nc, sizeof(__i_node*)));
         if (ibeg == nullptr)
             __throw_bad_alloc();