Merge branch 'upstream-KWSys' into update-kwsys

* upstream-KWSys:
  KWSys 2019-02-05 (65802a20)

Source/kwsys/SystemInformation.cxx

@@ -4424,7 +4424,8 @@ bool SystemInformationImplementation::ParseSysCtl()
                       &count) == KERN_SUCCESS) {
     len = sizeof(value);
     err = sysctlbyname("hw.pagesize", &value, &len, KWSYS_NULLPTR, 0);
-    int64_t available_memory = vmstat.free_count * value;
+    int64_t available_memory =
+      (vmstat.free_count + vmstat.inactive_count) * value;
     this->AvailablePhysicalMemory =
       static_cast<size_t>(available_memory / 1048576);
   }