x86 mterp: fix cherry-pick/merge, issue 3095771

Bug http://b/issue?id=3095771

Change
https://android-git.corp.google.com/g/#change,70700
was a cherry-pick/merge of
https://android-git.corp.google.com/g/#change,70388

It was not properly merged, and resulting in the register holding
the object head to be trashed (and subsequently broke GC).

Change-Id: Ic480104e3a643a5b744d36eb0aefaedd3e4f925c
2 files changed