Analyse an implode() function call to see if it contains a specific code pattern
to dynamically create placeholders.

The pattern we are searching for is:
`implode( ',', array_fill( 0, count( $something ), '%s' ) )`

This pattern presumes unquoted placeholders!

@since 0.14.0

@param int $implode_token The stackPtr to the implode function call.

@return bool True if the pattern is found, false otherwise.