dereferencing null

[Nathan M. Swan]

On Saturday, 3 March 2012 at 02:51:41 UTC, Walter Bright wrote:
> Adding in software checks for null pointers will dramatically 
> slow things down.

What about the debug/release difference? Isn't the point of debug 
mode to allow checks such as assert, RangeError, etc? 
"Segmentation fault: 11" prevents memory from corrupting, but it 
isn't helpful in locating a bug.