machinst x64: enable two more Rust tests;

Fixed by the grand ABI refactoring, h/t @cfallin.

tests/all/iloop.rs

@@ -99,7 +99,6 @@ fn loop_interrupt_from_afar() -> anyhow::Result<()> {
 }
 
 #[test]
-#[cfg_attr(feature = "experimental_x64", ignore)] // TODO #2079 interrupts in wasmtime
 fn function_interrupt_from_afar() -> anyhow::Result<()> {
     // Create an instance which calls an imported function on each iteration of
     // the loop so we can count the number of loop iterations we've executed so

tests/all/stack_overflow.rs

@@ -2,7 +2,6 @@ use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
 use wasmtime::*;
 
 #[test]
-#[cfg_attr(feature = "experimental_x64", ignore)] // TODO #2079 require probe stacks
 fn host_always_has_some_stack() -> anyhow::Result<()> {
     static HITS: AtomicUsize = AtomicUsize::new(0);
     // assume hosts always have at least 512k of stack