Auto merge of #14787 - HKalbasi:mir2, r=HKalbasi

MIR episode 5

This PR inits drop support (it is very broken at this stage, some things are dropped multiple time, drop scopes are wrong, ...) and adds stdout support (`println!` doesn't work since its expansion is dummy, but `stdout().write(b"hello world\n")` works if you use `RA_SYSROOT_HACK`) for interpreting. There is no useful unit test that it can interpret yet, but it is a good sign that it didn't hit a major road block yet.

In MIR lowering, it adds support for slice pattern and anonymous const blocks, and some fixes so that we can evaluate `SmolStr::new_inline` in const eval. With these changes, 57 failed mir body remains.

crates/hir-expand/src/name.rs

@@ -376,6 +376,7 @@ pub mod known {
         deref,
         div_assign,
         div,
+        drop,
         fn_mut,
         fn_once,
         future_trait,