Add optional LOG_TASK logging for MachVMMemory::PageSize() task_info call failure.

llvm-svn: 178954
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
index 8149003..2d2c5b1 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
@@ -44,6 +44,10 @@
             {
                 return vm_info.page_size;
             }
+            else
+            {
+                DNBLogThreadedIf(LOG_TASK, "MachVMMemory::PageSize task_info call failed to get page size, TASK_VM_INFO %d, TASK_VM_INFO_COUNT %d, kern return %d", TASK_VM_INFO, TASK_VM_INFO_COUNT, kr);
+            }
         }
 #endif
         m_err = ::host_page_size( ::mach_host_self(), &m_page_size);