x86/x86-64: Simplify codegen using helper functions.

Simplify comparisons and array element address calculations.

Test: m test-art-host
Change-Id: I2a3f54a3638cf4c24d9e3cac83daba47f0723f72
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 693d0b8..7108676 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -510,6 +510,18 @@
   void Compare32BitValue(CpuRegister dest, int32_t value);
   void Compare64BitValue(CpuRegister dest, int64_t value);
 
+  // Compare int values. Supports only register locations for `lhs`.
+  void GenerateIntCompare(Location lhs, Location rhs);
+
+  // Compare long values. Supports only register locations for `lhs`.
+  void GenerateLongCompare(Location lhs, Location rhs);
+
+  // Construct address for array access.
+  static Address ArrayAddress(CpuRegister obj,
+                              Location index,
+                              ScaleFactor scale,
+                              uint32_t data_offset);
+
   Address LiteralCaseTable(HPackedSwitch* switch_instr);
 
   // Store a 64 bit value into a DoubleStackSlot in the most efficient manner.