[MIPS] Refactoring code for quick compiler

Code from compiler/dex/quick/mips64 is merged with code
in mips folder.

Change-Id: I785983c21549141306484647da86a0bb4815daaa
diff --git a/compiler/dex/quick/quick_compiler.cc b/compiler/dex/quick/quick_compiler.cc
index 1673312..6d28984 100644
--- a/compiler/dex/quick/quick_compiler.cc
+++ b/compiler/dex/quick/quick_compiler.cc
@@ -45,7 +45,6 @@
 #include "dex/quick/arm/backend_arm.h"
 #include "dex/quick/arm64/backend_arm64.h"
 #include "dex/quick/mips/backend_mips.h"
-#include "dex/quick/mips64/backend_mips64.h"
 #include "dex/quick/x86/backend_x86.h"
 
 namespace art {
@@ -808,10 +807,9 @@
       mir_to_lir = Arm64CodeGenerator(cu, cu->mir_graph.get(), &cu->arena);
       break;
     case kMips:
-      mir_to_lir = MipsCodeGenerator(cu, cu->mir_graph.get(), &cu->arena);
-      break;
+      // Fall-through.
     case kMips64:
-      mir_to_lir = Mips64CodeGenerator(cu, cu->mir_graph.get(), &cu->arena);
+      mir_to_lir = MipsCodeGenerator(cu, cu->mir_graph.get(), &cu->arena);
       break;
     case kX86:
       // Fall-through.