RFR: 8293065: Zero build failure on AArch64 and RISCV64 after JDK-8293007

[Feilong Jiang]

[JDK-8293007](https://bugs.openjdk.org/browse/JDK-8293007) changes the `AARCH64_PORT_ONLY` macro into `AARCH64`, which is not an equivalent replacement.
This patch also fixes the same zero build failure on RISCV64.

Testing:

- Linux AArch64 zero release build
- Linux AArch64 server release build
- Linux RISCV64 zero release build
- Linux RISCV64 server release build

-------------

Commit messages:
 - Fix riscv64/aarch64 zero build

Changes: https://git.openjdk.org/jdk/pull/10075/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10075&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293065
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10075.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10075/head:pull/10075

PR: https://git.openjdk.org/jdk/pull/10075