ART: Extract JNI macro assembler for arm

Extract the JNI assembler parts from the regular assembler.

Change-Id: Ice39ffeb854f8651e93443dd69f4c9e0e802975c
Test: m test-art-target (N6)
diff --git a/compiler/utils/jni_macro_assembler.cc b/compiler/utils/jni_macro_assembler.cc
index 1acc90c..9b16b98 100644
--- a/compiler/utils/jni_macro_assembler.cc
+++ b/compiler/utils/jni_macro_assembler.cc
@@ -20,8 +20,7 @@
 #include <vector>
 
 #ifdef ART_ENABLE_CODEGEN_arm
-#include "arm/assembler_arm32.h"
-#include "arm/assembler_thumb2.h"
+#include "arm/jni_macro_assembler_arm.h"
 #endif
 #ifdef ART_ENABLE_CODEGEN_arm64
 #include "arm64/assembler_arm64.h"
@@ -58,9 +57,8 @@
   switch (instruction_set) {
 #ifdef ART_ENABLE_CODEGEN_arm
     case kArm:
-      return MacroAsm32UniquePtr(new (arena) arm::Arm32Assembler(arena));
     case kThumb2:
-      return MacroAsm32UniquePtr(new (arena) arm::Thumb2Assembler(arena));
+      return MacroAsm32UniquePtr(new (arena) arm::ArmJNIMacroAssembler(arena, instruction_set));
 #endif
 #ifdef ART_ENABLE_CODEGEN_mips
     case kMips: