Spellchecking some comments

This PR attempts to clean up some minor spelling mistakes in comments

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -164,7 +164,7 @@ impl<Tag> Allocation<Tag> {
         let bytes = Box::<[u8]>::try_new_zeroed_slice(size.bytes_usize()).map_err(|_| {
             // This results in an error that can happen non-deterministically, since the memory
             // available to the compiler can change between runs. Normally queries are always
-            // deterministic. However, we can be non-determinstic here because all uses of const
+            // deterministic. However, we can be non-deterministic here because all uses of const
             // evaluation (including ConstProp!) will make compilation fail (via hard error
             // or ICE) upon encountering a `MemoryExhausted` error.
             if panic_on_fail {