Fix compatibility for OnUpdate, OnDelete and other clauses (#331, #392, #393) (#642)

[eurekaka]

cherry-pick #642 to 3.1.6, since 3.1.6 has just rebased release-3.0 which needs this parser change.

[kennytm]

We shouldn't have a release-3.1.6 branch, only release-3.1 or release-3.0 branch 🤔

[eurekaka]

release-3.1 would be deprecated soon, and release-3.1.6 is the replacement. @coocood please help explain the existence of release-3.1.6 here.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-3.1.6@80a9970). Click here to learn what that means.
The diff coverage is 8.51%.

@@               Coverage Diff                @@
##             release-3.1.6     #647   +/-   ##
================================================
  Coverage                 ?   64.21%           
================================================
  Files                    ?       31           
  Lines                    ?    10962           
  Branches                 ?        0           
================================================
  Hits                     ?     7039           
  Misses                   ?     3513           
  Partials                 ?      410

Impacted Files	Coverage Δ
parser.go	86.45% <ø> (ø)
misc.go	96.49% <ø> (ø)
yy_parser.go	83.33% <100%> (ø)
ast/ddl.go	43.15% <4.44%> (ø)

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[kennytm]

release-3.1 would be deprecated soon, and release-3.1.6 is the replacement

Then the branch name makes no sense since the next versions are 3.0.6 and 3.1.0.

[coocood]

@kennytm release-3.1.6 would be renamed to release-3.1 later

[coocood]

LGTM