Description:
------------
PDO SQLite still contains the following configure test in its config.m4:

  dnl Solaris fix
  PHP_CHECK_LIBRARY(rt, fdatasync, [PHP_ADD_LIBRARY(rt,, PDO_SQLITE_SHARED_LIBADD)])

This check can be dropped, because the fdatasync was only used inside the bundled sqlite, but starting with 5.3 sqlite is no longer bundled but expected as an external dependency. So libsqlite3.so itself would have that dependency, but the pdo-sqlite.so extension should not have an entry for -lrt any more.

You can simply drop the two lines from ext/pdo_sqlite/config.m4 (and regenerate configure).

This applies to any PHP version starting with 5.3 and up until 7.4beta1.

Note that older bugs are about fdatasync being used but -lrt missing. This is about fdatasync no longer being used but -lrt still present.