gh-119726: generate and patch AArch64 trampolines

[diegorusso]

AArch64 trampolines are now generated at runtime at the end of every trace.

• Issue: JIT: improve AArch64 code generation #119726

[brandtbucher]

This is great! I'd like to see this mechanism used across all platforms for symbols in the "global offset table" too (but that can be a separate project).

It's a clear improvement for the affected platforms:

• aarch64-unknown-linux-gnu: 0.8% faster, 0.6% less memory.
• aarch64-apple-darwin: 1.5% faster, 0.8% less memory.

Here's an initial review of the Python code. I'll dig into the C code tomorrow.

[diegorusso]

It's a clear improvement for the affected platforms:

• aarch64-unknown-linux-gnu: 0.8% faster, 0.6% less memory.
• aarch64-apple-darwin: 1.5% faster, 0.8% less memory.

Well better than nothing :)

[brandtbucher]

Thanks for your patience! This is looking really good.

A few thoughts I had reading the C code:

[brandtbucher]

Thanks!