Khmer royal inscriptions name Suryavarman II's posthumous title and record his military campaigns and his temple building at Angkor Wat, but as with other Khmer god-kings his personal birth is not part of the epigraphic record, which speaks in terms of reign and religious dedication rather than biography.
What would resolve this A dated Khmer inscription naming Suryavarman II's age or birth before his accession, distinct from the reign and campaign dates his own inscriptions record.
OpenKhmer history, Angkorian epigraphyWikipedia contributors, Suryavarman II (reference article)