There's no Token::Period in such situation, so fractional part (from sec) was silently truncated.
Can't uncomment the test yet, because parse_timestamp() is effectively
unused: the code added to parse_value() in 5abd9e7dec
was wrong as it attempted to handle unquoted date/time literals. One
part of it was commented out earlier, the other can't work as far as I
can see, as it tries to parse a Number token - `([0-9]|\.)+` - as a
timestamp, so I removed it as well.
1) Simplified the bit in parse_datatype()
2) Made sure it was covered by the test (the "public.year" bit)
2a) ...the rest of changes in the test are to fix incorrect variable
names: c_name/c_lat/c_lng were copy-pasted from a previous test.
3) Removed the branch from parse_pg_cast, which duplicated what
parse_data_type already handled (added in the same commit even
2007995938 )
