[PATCH] Adding skeleton for unit testing Hexagon Code Emission

[Chad Rosier]

Sorry for the multiple reviews..  Please address these as well.

================
Comment at: lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp:64
@@ +63,3 @@
+  HexagonMCInst const &HMB = static_cast<HexagonMCInst const &>(MI);
+  uint64_t Binary;
+  Binary = getBinaryCodeForInstr(HMB, Fixups, STI);
----------------
How about just:

uint64_t Binary = getBinaryCodeForInstr(HMB, Fixups, STI) | getPacketBits(HMB);

================
Comment at: lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp:67
@@ +66,3 @@
+  Binary |= getPacketBits(HMB);
+  assert(HMB.getDesc().getSize() == 4);
+  emitLittleEndian(Binary, OS);
----------------
assert(cond && "msg");

http://reviews.llvm.org/D5523