Add out-of-line constant pool support to Arm.

src/v8globals.h

Index: src/v8globals.h
diff --git a/src/v8globals.h b/src/v8globals.h
index 7d8d1b7e400794b7105314445d4bde0fad09ab29..ded2200356a66df3688bbe7d99547d5ebfa6e6e9 100644
--- a/src/v8globals.h
+++ b/src/v8globals.h
@@ -238,7 +238,18 @@ struct CodeDesc {
   int buffer_size;
   int instr_size;
   int reloc_size;
+  int constant_pool_64bit_count;
+  int constant_pool_code_ptr_count;
+  int constant_pool_heap_ptr_count;
+  int constant_pool_32bit_count;
   Assembler* origin;
+
+  inline bool has_empty_constant_pool() const {
+    return constant_pool_64bit_count == 0 &&
+           constant_pool_code_ptr_count == 0 &&
+           constant_pool_heap_ptr_count == 0 &&
+           constant_pool_32bit_count == 0;
+  }
 };