when needs_return_buffer == true and result_size() > 2, the 3rd return value
is placed in r4 register. But when debug code is emited, it uses r4 register
for checking exceptions, which corrupts the 3rd return value.

R=joransiu@ca.ibm.com, mbrandy@us.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1839663002

Cr-Commit-Position: refs/heads/master@{#35084}