Get rid of NULLs in core/

core/fxcrt/include/fx_system.h

Index: core/fxcrt/include/fx_system.h
diff --git a/core/fxcrt/include/fx_system.h b/core/fxcrt/include/fx_system.h
index 61acd73492a7ed895aadb2d15e46b2cf1918e54f..97ad85b2ef85027ab23d9e202228b21eee13d957 100644
--- a/core/fxcrt/include/fx_system.h
+++ b/core/fxcrt/include/fx_system.h
@@ -91,8 +91,8 @@ static_assert(TRUE == true, "true_needs_to_be_true");
 static_assert(FALSE == false, "false_needs_to_be_false");
 #endif
 
-#ifndef NULL
-#define NULL 0
+#ifndef nullptr

[Tom Sepez, 2016/06/02 20:09:49]

Let's not do this.  Let's keep it NULL for things that may include this.

[Lei Zhang, 2016/06/07 07:33:24]

I ended up removing this in one of the later patch sets and all the trybots were
green.

+#define nullptr 0
 #endif
 
 #ifndef ASSERT