i#1577: fix uninitialized var warning on stack read
i#1577: fix uninitialized var warning on stack read

Fixes a thorny issue with compiler warnings on test code that's trying to
read from the stack from C code.  This fixes the warning on a gcc 4.8.2
cross-compile to ARM.  There still seems to be a warning on gcc 4.5 so we
will leave the issue open.

Review-URL: https://codereview.appspot.com/256720043

bl4ckic3/dynamorio,bl4ckic3/dynamorio,AmesianX/dynamorio,bl4ckic3/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,daksunt/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,daksunt/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,code4bones/dynamorio,daksunt/dynamorio,daksunt/dynamorio,bl4ckic3/dynamorio,code4bones/dynamorio,daksunt/dynamorio