Add an address size bitfield to the isa description and the ExtMachInst

--HG--
extra : convert_revision : f8907ef5ef77e050eeb00d895263b49da4a9b6e9

src/arch/x86/isa/bitfields.isa

@@ -87,3 +87,4 @@ def bitfield SIB_INDEX sib.index;
 def bitfield SIB_BASE sib.base;
 
 def bitfield OPSIZE opSize;
+def bitfield ADDRSIZE addrSize;

src/arch/x86/types.hh

@@ -149,7 +149,8 @@ namespace X86ISA
 
         //The effective operand size.
         uint8_t opSize;
-        //The
+        //The effective address size.
+        uint8_t addrSize;
     };
 
     inline static std::ostream &