sal: CPU now knows extended trace registers

The extended trace register list is needed in multiple locations; the CPU
class is the logical module to contain this information.

Increased number of x86 registers to be traced; we can remove those
that prove unusable for fault-space pruning later on.

Change-Id: Ic46ecdbc55167a6d92872c190317fc0d1a3ad92d

src/core/sal/Register.hpp

@@ -23,7 +23,9 @@ enum RegisterType {
 	RT_GP,   //!< general purpose
 	RT_FP,   //!< floating point register
 	RT_IP,   //!< program counter / instruction pointer
-	RT_ST    //!< status register
+	RT_ST,   //!< status register
+
+	RT_TRACE //!< registers to be recorded in an extended trace
 };
 
 /**