Make ANGLE program version only dependent on data that matters This change introduces a new variable ANGLE_PROGRAM_VERSION to track the version of ANGLE source files that affect shader program serialization/deserialization. This change include more source files than necessary, to serve the purpose of a conservative jumping off point. We will narrow down the list of files for ANGLE_PROGRAM_VERSION hash generation in the future. Add a new script program_serialize_data_version.py that will be triggered during the build when the related source files changed. The script will generate a hash and the hash size from the related source files. In program serialization/deserialization and cache key generation, we will use this hash value instead of the entire ANGLE git hash. When the hash value changed, we know that the related source files changed, and we should invalidate the program cache and re-generate the blob cache / program binary. Bug: angleproject:4981 Change-Id: I2fb609416738d459d3289190c232c2d797ba58e3 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4072215 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Cody Northrop <cnorthrop@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Yuxin Hu <yuxinhu@google.com>