GenCode - Reduce merge-conflicts on AllCoreTables

[totten]

The previous checksum was based on the full schema spec. This is
technically safe, but many irrelevant schema changes (such as editing field
comments) will ding the checksum.

The main goal here is to avoid $template->run() (line ~44) and its
code-beautifier (which is expensive/slow). This revised algorithm for
needsUpdate() should:

• Still be "fast enough" (given that it's a singular file built from a simple template)
• Still be "accurate enough" (given that getRaw() is a fair predictor of run())
• Be less prone to merge-conflics (given that it doesn't use the checksum)

Ping @colemanw

[colemanw]

So does this unconditionally make the checksum in AllCoreTables.data.php "IGNORE"? or only when the tables don't change?

[totten]

Yes, the checksum is just set to IGNORE. We could probably rip out all references to the checksums from the php/tpl. (The general idea of this change is to ignore the checksum -- because the remaining test (isApproxPhpMatch(file_get(), getRaw())) should still fast/good-enough for this particular file.)

In the near-term, I think this means that the pre-existing AllCoreTables.data.php would remain in place (despite the fact that its checksum is different/old). Eventually, when there is a substantive change, the file would regenerate, and the checksum would appear as literal IGNORE.