Fix two issues in the interpreter entry for 64 bit return values on
32 bit platforms. First, the effect chain was slightly incorrect, second
the order of the returned values was wrong.

Also add a test case for this.
Tested on x64, ia32 and s390.

Plus drive-by fix in Int64Lowering to reuse global constants for
big-endian/little-endian disambiguation.

R=titzer@chromium.org
BUG=v8:5822

Review-Url: https://codereview.chromium.org/2731713002
Cr-Commit-Position: refs/heads/master@{#43654}