Debugger: Fix array access with LLDB if index is a long

Triggered with the QGraphicsPolygonItem dumper on Linux.

Change-Id: I1374ca308c732eb5c25da959d8b499515ed72e66
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>

share/qtcreator/debugger/lldbbridge.py

@@ -69,7 +69,7 @@ Value = lldb.SBValue
 
 def impl_SBValue__add__(self, offset):
     if self.GetType().IsPointerType():
-        if isinstance(offset, int):
+        if isinstance(offset, int) or isinstance(offset, long):
             pass
         else:
             offset = offset.GetValueAsSigned()