Debugger: Fix dumper test when inferior runs under wow64.

When the inferior runs under wow64, DebugBreak throws a wow64 breakpoint.
These has to be ignored because they are also thrown on every 32 bit library
load. To make sure the debugger breaks DebugBreak is replaced by a null
pointer dereference.

Change-Id: I0c0985558da1c355c1fc62a2fc5f736e54e843ce
Reviewed-by: Christian Stenger <christian.stenger@digia.com>