stats: fix histogram bound overflow error

[alivxxx]

What problem does this PR solve?

When we have a table with unsigned primary key and have a query like select count(*) from t, the scan range of query will be [-inf, +inf], like a signed primary key, not [0,+inf](it should be another problem though). So when updating the histogram using feedback, the -inf value will be stored into uint64, which will overflow the histogram value ranges. Then when reading stats from a table, there will be an error message like Error occurred when read table stats for table sbtest1. The error message is [types:1690]constant 18446744071562067968 overflows int.

What is changed and how it works?

• Get the min and max allowd value using the histogram value type, not the feedback datum kind, to avoid the miss matched type.
• When decoding the query feedback for primary key, we will store the value using the correct type(signed or unsigned).

Check List

Tests

• Unit test

Code changes

• Has exported function/method change

Side effects

• None

Related changes

• Need to cherry-pick to the release branch

[codecov-io]

Codecov Report

Merging #8984 into master will increase coverage by 0.03%.
The diff coverage is 72.72%.

@@            Coverage Diff             @@
##           master    #8984      +/-   ##
==========================================
+ Coverage   67.51%   67.55%   +0.03%     
==========================================
  Files         363      363              
  Lines       75264    75270       +6     
==========================================
+ Hits        50818    50851      +33     
+ Misses      19949    19929      -20     
+ Partials     4497     4490       -7

Impacted Files	Coverage Δ
statistics/update.go	84.16% <100%> (ø)	⬆️
statistics/feedback.go	73.32% <72.09%> (+1.02%)	⬆️
statistics/histogram.go	82.34% <0%> (+0.39%)	⬆️
executor/join.go	78.29% <0%> (+0.4%)	⬆️
expression/schema.go	94.95% <0%> (+0.84%)	⬆️
store/tikv/lock_resolver.go	42.65% <0%> (+0.94%)	⬆️
ddl/delete_range.go	74.28% <0%> (+1.71%)	⬆️
statistics/scalar.go	82.88% <0%> (+1.8%)	⬆️
store/mockstore/mocktikv/pd.go	58.97% <0%> (+7.69%)	⬆️
... and 2 more

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[winoros]

lgtm

[breezewish]

/run-integration-common-test

[zz-jason]

LGTM

[zz-jason]

/run-all-tests