ARM JDK from AdoptJDK – Info Java

OpenJDK has a few modes for AArch64/ARM64: 1) Zero, interpreted mode, available since forever (?); 2) AArch64 port that includes C1 and C2 compilers contributed by Red Hat in 9 (and shipped in RHEL/Fedora starting from 8); 3) Unified ARM32/ARM64 port that includes C1 and C2 compilers contributed by Oracle in 9, and ARM64 part seems to be on its way out.

I would guess jdk-8u181-linux-arm64-vfp-hflt is (3) before it was contributed to open, and OpenJDK10-aarch64-Linux-* is (2).