Fix wrong guard values for 64 bit.

I added the code to force alignments of 8 for 32 bit and 16 for 64 bit,
but I missed a couple of tests that failed due to this change. Fix the
failing tests.

Bug: 26739265

(cherry picked from commit 0e2a0265)

Change-Id: I21c3e26a340df6e427f06625e525b88b19b0cae1