parser: support some new syntax

[zier-one]

support followed syntax:

ALTER TABLE t LOCK [=] lock_type

ALTER TABLE t ALGORITHM [=] algorithm_type

ALTER TABLE t ALTER COLUMN a SET DEFAULT (expr)

ALTER TABLE t ADD CONSTRAINT aaa CHECK (expr) [NOT [ENFORCED]]
CREATE TABLE t (a INT CHECK(expr) [NOT [ENFORCED]])
CREATE TABLE t (a INT CHECK(expr) NOT NULL)
(CHECK only parsed but not implement function)
Here I refer to the implementation of MySQL:
https://github.com/mysql/mysql-server/blob/c000dcf1a9b2ee4a4f986dde08c1f6e1b6461a18/sql/sql_yacc.yy#L6733

BTW： Thanks for the guidance from @kennytm

What problem does this PR solve?

Improve the compatibility of tidb parser

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
  i tested SET DEFAULT (expr) in tidb which use the parser of this commi.
  we support const value like : (1+1),(1*1). but we don't support functionexpr like: (now())
• No code

Code changes

• Has exported function/method change
  none
• Has exported variable/fields change
  add a new lex token named 'enforced'
• Has interface methods change
  none

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation
• Need to be included in the release note

[zier-one]

/run-all-tests

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@ded7e04). Click here to learn what that means.
The diff coverage is 63.63%.

@@           Coverage Diff            @@
##             master    #392   +/-   ##
========================================
  Coverage          ?   70.1%           
========================================
  Files             ?      32           
  Lines             ?    7405           
  Branches          ?       0           
========================================
  Hits              ?    5191           
  Misses            ?    1701           
  Partials          ?     513

Impacted Files	Coverage Δ
parser.go	70.58% <ø> (ø)
misc.go	96.42% <ø> (ø)
yy_parser.go	83.33% <100%> (ø)
ast/ddl.go	77.56% <55.55%> (ø)

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[codecov]

Codecov Report

Merging #392 into master will increase coverage by 0.05%.
The diff coverage is 77.77%.

@@            Coverage Diff             @@
##           master     #392      +/-   ##
==========================================
+ Coverage    70.1%   70.16%   +0.05%     
==========================================
  Files          32       32              
  Lines        7399     7433      +34     
==========================================
+ Hits         5187     5215      +28     
- Misses       1700     1703       +3     
- Partials      512      515       +3

Impacted Files	Coverage Δ
parser.go	70.58% <ø> (ø)	⬆️
misc.go	96.42% <ø> (ø)	⬆️
yy_parser.go	83.33% <100%> (+0.26%)	⬆️
ast/ddl.go	77.73% <76.47%> (+0.08%)	⬆️

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[zier-one]

@kennytm @tiancaiamao PTAL

[zier-one]

@imtbkcat PTAL

[tiancaiamao]

integration-test fail

[kennytm]

Some code is spaced badly. Rest LGTM.

[zier-one]

@kennytm @tiancaiamao PTAL again

[kennytm]

LGTM

[tiancaiamao]

LGTM