write_primval used to leak memory if the destination was ByRef
write_primval used to leak memory if the destination was ByRef

instead of duplicating all the code from `write_value`, we forward to it.
aidancully/rust,tsion/miri,aidancully/rust,GBGamer/rust,rust-lang/miri,graydon/rust,GBGamer/rust,GBGamer/rust,graydon/rust,rust-lang/miri,graydon/rust,rust-lang/miri,aidancully/rust,GBGamer/rust,GBGamer/rust,rust-lang/miri,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust