x86: Debugger can now use dr3

headers/private/kernel/arch/x86/arch_thread.h

@@ -62,7 +62,7 @@ void arch_syscall_64_bit_return_value(void);
 static inline void
 arch_thread_set_current_thread(Thread* t)
 {
-	asm volatile("mov %0, %%gs:0" : : "r" (t));
+	asm volatile("mov %0, %%gs:0" : : "r" (t) : "memory");
 }
 
 

headers/private/kernel/arch/x86/arch_user_debugger.h

@@ -9,12 +9,7 @@
 #define ARCH_INIT_USER_DEBUG x86_init_user_debug
 
 // number of breakpoints the CPU supports
-// On 32-bit, DR3 is used to hold the Thread*.
-#ifdef __x86_64__
-#	define X86_BREAKPOINT_COUNT		4
-#else
-#	define X86_BREAKPOINT_COUNT		3
-#endif
+#define X86_BREAKPOINT_COUNT		4
 
 // debug status register DR6
 enum {