Fix inappropriate uses of atol()

Fix inappropriate uses of atol()

Some code using atol() would not work correctly if sizeof(long)==4:

- src/bin/pg_basebackup/pg_basebackup.c: Would miscount size of a
  tablespace over 2 TB.

- src/bin/pg_basebackup/streamutil.c: Would truncate a timeline ID
  beyond INT32_MAX.

- src/bin/pg_rewind/libpq_source.c: Would miscount size of files
  larger than 2 GB (but this currently cannot happen).

Replace these with atoll().

In one case, the use of atol() did not result in incorrect behavior
but seems inconsistent with related code:

- src/interfaces/ecpg/ecpglib/execute.c: Gratuitous, since it
  processes a value from pg_type.typlen, which is int16.

Replace this with atoi().

Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/a52738ad-06bc-4d45-b59f-b38a8a89de49%40eisentraut.org