Add CURRENT_TIMESTAMP function, this time missing in the newer genera…

…ted functions-mysql8.ini. Closes #1951

out/functions-mysql8.ini

@@ -194,6 +194,11 @@ description=Creates a digest from the given string using the given digest type,
 declaration=
 category=Window Functions
 description=Returns the cumulative distribution of a value within a group of values;\nthat is, the percentage of partition values less than or equal to the value\nin the current row
+[CURRENT_TIMESTAMP]
+name=CURRENT_TIMESTAMP
+declaration=
+category=Date and Time Functions
+description=CURRENT_TIMESTAMP and CURRENT_TIMESTAMP() are synonyms for NOW().
 [CURDATE]
 declaration=
 category=Date and Time Functions