Support LIMIT clause in DB2 and DB2i

Turns out that DB2 documentation does mention the LIMIT clause,
but it's sneakily hidden at the bottom of the documentation page
and not included to the syntax diagram at the top.

src/languages/db2/db2.formatter.ts

@@ -14,6 +14,7 @@ const reservedClauses = expandPhrases([
   'HAVING',
   'PARTITION BY',
   'ORDER BY [INPUT SEQUENCE]',
+  'LIMIT',
   'OFFSET',
   'FETCH NEXT',
   'FOR UPDATE [OF]',

src/languages/db2i/db2i.formatter.ts

@@ -15,6 +15,7 @@ const reservedClauses = expandPhrases([
   'HAVING',
   'PARTITION BY',
   'ORDER [SIBLINGS] BY [INPUT SEQUENCE]',
+  'LIMIT',
   'OFFSET',
   'FETCH {FIRST | NEXT}',
   'FOR UPDATE [OF]',

test/db2.test.ts

@@ -19,7 +19,7 @@ describe('Db2Formatter', () => {
   behavesLikeDb2Formatter(format);
 
   supportsComments(format);
-  supportsLimiting(format, { fetchNext: true, offset: true });
+  supportsLimiting(format, { limit: true, fetchNext: true, offset: true });
   supportsCreateTable(format);
   supportsAlterTable(format, {
     addColumn: true,

test/db2i.test.ts

@@ -16,7 +16,7 @@ describe('Db2iFormatter', () => {
   behavesLikeDb2Formatter(format);
 
   supportsComments(format, { nestedBlockComments: true });
-  supportsLimiting(format, { fetchNext: true, fetchFirst: true, offset: true });
+  supportsLimiting(format, { limit: true, fetchNext: true, fetchFirst: true, offset: true });
   supportsCreateTable(format, { orReplace: true });
   supportsAlterTable(format, {
     addColumn: true,