misc: Using smart pointers for memory Requests

This patch is changing the underlying type for RequestPtr from Request*
to shared_ptr<Request>. Having memory requests being managed by smart
pointers will simplify the code; it will also prevent memory leakage and
dangling pointers.

Change-Id: I7749af38a11ac8eb4d53d8df1252951e0890fde3
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/10996
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

util/tlm/src/sc_master_port.cc

@@ -47,8 +47,9 @@ PacketPtr
 SCMasterPort::generatePacket(tlm::tlm_generic_payload& trans)
 {
     Request::Flags flags;
-    auto req = new Request(trans.get_address(), trans.get_data_length(), flags,
-                           owner.masterId);
+    auto req = std::make_shared<Request>(
+        trans.get_address(), trans.get_data_length(), flags,
+        owner.masterId);
 
     MemCmd cmd;