expression: handle ENUM in builtin function Values()

[zz-jason]

Signed-off-by: Jian Zhang zjsariel@gmail.com

What problem does this PR solve?

fix #9165

What is changed and how it works?

handle ENUM in builtinValuesStringSig

Check List

Tests

• Unit test

Related changes

• Need to cherry-pick to the release branch

[codecov-io]

Codecov Report

Merging #9225 into master will decrease coverage by <.01%.
The diff coverage is 77.77%.

@@            Coverage Diff             @@
##           master    #9225      +/-   ##
==========================================
- Coverage   67.26%   67.25%   -0.01%     
==========================================
  Files         371      371              
  Lines       77223    77222       -1     
==========================================
- Hits        51943    51935       -8     
- Misses      20642    20647       +5     
- Partials     4638     4640       +2

Impacted Files	Coverage Δ
expression/column.go	77.4% <ø> (+1.57%)	⬆️
expression/builtin_other.go	65.45% <77.77%> (+0.09%)	⬆️
store/tikv/scan.go	73.94% <0%> (-3.37%)	⬇️
ddl/delete_range.go	77.77% <0%> (-1.59%)	⬇️
store/tikv/lock_resolver.go	41.7% <0%> (-0.95%)	⬇️
executor/index_lookup_join.go	77.28% <0%> (-0.64%)	⬇️
executor/executor.go	67.03% <0%> (-0.28%)	⬇️
executor/join.go	78.38% <0%> (+0.52%)	⬆️
expression/schema.go	94.53% <0%> (+0.78%)	⬆️

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[zz-jason]

/run-all-tests

[eurekaka]

LGTM

[alivxxx]

LGTM

[zz-jason]

/run-all-tests

[zz-jason]

/run-unit-test