gltrace: Make code 64-bit safe.

Currently, the trace API passes the pointers that need to be
patched up via 32 bit integers. Such code will not be 64 bit safe.
This patch sends all pointers in a separate array of pointers
for the fixup calls to read from.

Change-Id: If975333f11a6f6f9a74fba57de328affaed452a5

Author: vsiva