ARM: Use 64-bit literals for LoadDImmediate().

And rewrite the medium-range long/fp literal to use
MOVW+ADD+LDRD/VLDR because the old instruction sequence
was broken if the "ADD ip, pc" was not 4-byte aligned.

Test: assembler_thumb2_test has been updated. Standard
      ART test suite has been run on host and Nexus 5.
Change-Id: I37c6a62aa6e77c6a9701b5a1fb4db2e666c1eae9
diff --git a/compiler/utils/arm/assembler_arm32.h b/compiler/utils/arm/assembler_arm32.h
index 8726ac8..554dd23 100644
--- a/compiler/utils/arm/assembler_arm32.h
+++ b/compiler/utils/arm/assembler_arm32.h
@@ -270,6 +270,7 @@
 
   // Load and Store. May clobber IP.
   void LoadImmediate(Register rd, int32_t value, Condition cond = AL) OVERRIDE;
+  void LoadDImmediate(DRegister dd, double value, Condition cond = AL) OVERRIDE;
   void MarkExceptionHandler(Label* label) OVERRIDE;
   void LoadFromOffset(LoadOperandType type,
                       Register reg,