[riscv-port] RFR: 8278387: riscv: Implement UseHeavyMonitors consistently

Make hotspot always use inflated monitors consistently if the flag UseHeavyMonitors is true. The riscv platform should follow https://bugs.openjdk.java.net/browse/JDK-8276901. ------------- Commit messages: - 8278387: riscv: Implement UseHeavyMonitors consistently Changes: https://git.openjdk.java.net/riscv-port/pull/26/files Webrev: https://webrevs.openjdk.java.net/?repo=riscv-port&pr=26&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8278387 Stats: 129 lines in 6 files changed: 40 ins; 20 del; 69 mod Patch: https://git.openjdk.java.net/riscv-port/pull/26.diff Fetch: git fetch https://git.openjdk.java.net/riscv-port pull/26/head:pull/26 PR: https://git.openjdk.java.net/riscv-port/pull/26