x86_64: Unify 64-bit check in x86 compiler

Update x86-specific Gen64Bit() check with the CompilationUnit target64 field
which is set using unified Is64BitInstructionSet(InstructionSet) check.

Change-Id: Ic00ac863ed19e4543d7ea878d6c6c76d0bd85ce8
Signed-off-by: Elena Sayapina <elena.v.sayapina@intel.com>
diff --git a/compiler/dex/quick/x86/codegen_x86.h b/compiler/dex/quick/x86/codegen_x86.h
index 70382c7..21d7419 100644
--- a/compiler/dex/quick/x86/codegen_x86.h
+++ b/compiler/dex/quick/x86/codegen_x86.h
@@ -59,7 +59,7 @@
   };
 
  public:
-  X86Mir2Lir(CompilationUnit* cu, MIRGraph* mir_graph, ArenaAllocator* arena, bool gen64bit);
+  X86Mir2Lir(CompilationUnit* cu, MIRGraph* mir_graph, ArenaAllocator* arena);
 
   // Required for target - codegen helpers.
   bool SmallLiteralDivRem(Instruction::Code dalvik_opcode, bool is_div, RegLocation rl_src,
@@ -802,8 +802,6 @@
    */
   void AnalyzeInvokeStatic(int opcode, BasicBlock * bb, MIR *mir);
 
-  bool Gen64Bit() const  { return gen64bit_; }
-
   // Information derived from analysis of MIR
 
   // The compiler temporary for the code address of the method.
@@ -833,9 +831,6 @@
   // Epilogue increment of stack pointer.
   LIR* stack_increment_;
 
-  // 64-bit mode
-  bool gen64bit_;
-
   // The list of const vector literals.
   LIR *const_vectors_;