RFR: Add aarch64 specific lock/unlock tsan instruments

[Jie He]

On Thu, 7 May 2020 16:31:05 GMT, Arthur Eubanks <aeubanks at openjdk.org> wrote:

> What do you think about making the `16` based on the arch?
> 
> `assert((id_u8 & left_n_bits(16)) == 0, "jmethodID is not aligned");`

the assertion guarantees it's a 47-bit address, I think it's not neccessary for aarch64, I can add a AMD64_ONLY for it.

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

PR: https://git.openjdk.java.net/tsan/pull/9