Reland "riscv64: Add relative patcher."

This reverts commit 6aa484945f7c77aef73643a3a8aab3ac06ecaea1.

Reason for revert: Reland with a fix.

Change-Id: I2de4cc8c59f1ad9d0807470ab2336106dcef430a
Test: m  # aosp_cf_riscv64_phone-userdebug
Test: m test-art-host-gtest
Bug: 283082089
9 files changed