fixes to stack trace code under x64 (from work):

- displaying symbol values requires stack pointer, not frame pointer
- update debug_IsPointerBogus
- skip-n-frames code changed to skip-all-frames-up-to-func (more
reliable in the face of inlining)

debug.cpp: cleanup

This was SVN commit r6410.

source/ps/GameSetup/GameSetup.cpp

@@ -839,7 +839,7 @@ void EarlyInit()
 	// If you ever want to catch a particular allocation:
 	//_CrtSetBreakAlloc(321);
 
-	debug_set_thread_name("main");
+	debug_SetThreadName("main");
 	// add all debug_printf "tags" that we are interested in:
 	debug_filter_add("TIMER");