Fix finish command for PNaCl.

Since PNaCl hides base address, frame stack addresss may contain
base address or not depending on whether it comes from register
or stack frame.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3600
TEST= none
R=eaeltsin@google.com

Review URL: https://codereview.chromium.org/22399003
1 file changed