Fix up the base x86 fault object and create a fault to be generated by unimplemented instructions in their microcode. This is useful if certain variations of an instruction are implemented, but, for instance, it's memory based versions aren't.

--HG--
extra : convert_revision : 24e69c5a6a0af2d0cf67e858a051ae6624bb300f

src/arch/x86/faults.hh

@@ -65,12 +65,32 @@ namespace X86ISA
 {
     class X86Fault : public FaultBase
     {
+      protected:
+        const char * name()
+        {
+            return "generic_x86_fault";
+        }
+
         void invoke(ThreadContext * tc)
         {
             panic("X86 faults are not implemented!");
         }
     };
 
+    class UnimpInstFault : public FaultBase
+    {
+      public:
+        const char * name()
+        {
+            return "unimplemented_micro";
+        }
+
+        void invoke(ThreadContext * tc)
+        {
+            panic("Unimplemented instruction!");
+        }
+    };
+
     static inline Fault genPageTableFault(Addr va)
     {
         panic("Page table fault not implemented in x86!\n");