Fix: correctly destruct VIXL labels.

Bug: 27505766
Change-Id: I077465e3d308f4331e7a861902e05865f9d99835
diff --git a/compiler/optimizing/code_generator_x86.h b/compiler/optimizing/code_generator_x86.h
index 69a6253..1739eec 100644
--- a/compiler/optimizing/code_generator_x86.h
+++ b/compiler/optimizing/code_generator_x86.h
@@ -361,7 +361,7 @@
     return assembler_;
   }
 
-  uintptr_t GetAddressOf(HBasicBlock* block) const OVERRIDE {
+  uintptr_t GetAddressOf(HBasicBlock* block) OVERRIDE {
     return GetLabelOf(block)->Position();
   }