ruby: Rename pkt to m_pkt so it may be accessed via SLICC

Allow usage of packet class in ruby for convenience purposes. This may be
used to access members of the packet/request class (e.g., via helper
functions) and/or push protocol specific information to the packets
SenderState without needing to modify SLICC types and protocols in multiple
locations.

src/mem/protocol/RubySlicc_Types.sm

@@ -171,6 +171,7 @@ structure(RubyRequest, desc="...", interface="Message", external="yes") {
   int wfid,                  desc="Writethrough wavefront";
   HSAScope scope,            desc="HSA scope";
   HSASegment segment,        desc="HSA segment";
+  PacketPtr pkt,             desc="Packet associated with this request";
 }
 
 structure(AbstractEntry, primitive="yes", external = "yes") {

src/mem/ruby/slicc_interface/RubyRequest.hh

@@ -53,7 +53,7 @@ class RubyRequest : public Message
     int m_Size;
     PrefetchBit m_Prefetch;
     uint8_t* data;
-    PacketPtr pkt;
+    PacketPtr m_pkt;
     ContextID m_contextId;
     WriteMask m_writeMask;
     DataBlock m_WTData;
@@ -76,7 +76,7 @@ class RubyRequest : public Message
           m_Size(_len),
           m_Prefetch(_pb),
           data(_data),
-          pkt(_pkt),
+          m_pkt(_pkt),
           m_contextId(_core_id),
           m_scope(_scope),
           m_segment(_segment)
@@ -100,7 +100,7 @@ class RubyRequest : public Message
           m_Size(_len),
           m_Prefetch(_pb),
           data(_data),
-          pkt(_pkt),
+          m_pkt(_pkt),
           m_contextId(_core_id),
           m_writeMask(_wm_size,_wm_mask),
           m_WTData(_Data),
@@ -128,7 +128,7 @@ class RubyRequest : public Message
           m_Size(_len),
           m_Prefetch(_pb),
           data(_data),
-          pkt(_pkt),
+          m_pkt(_pkt),
           m_contextId(_core_id),
           m_writeMask(_wm_size,_wm_mask,_atomicOps),
           m_WTData(_Data),