Don't require a trivial move constructor and trivial destructor. This excludes
types that have declared themselves trivially relocatable by another means, like
std::unique_ptr. Instead use "is trivially relocatable" directly, which includes
all previous types as well as those that have opted in.
PiperOrigin-RevId: 523557136
Change-Id: Icea2dbb8f36f99623308155f2e5b1edd8e5bd36b