typos

src/eval_context.rs

@@ -455,7 +455,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                 if self.intrinsic_overflowing(bin_op, left, right, dest, dest_ty)? {
                     // There was an overflow in an unchecked binop.  Right now, we consider this an error and bail out.
                     // The rationale is that the reason rustc emits unchecked binops in release mode (vs. the checked binops
-                    // it emits in debug mode) is performance, but it doesn't cust us any performance in miri.
+                    // it emits in debug mode) is performance, but it doesn't cost us any performance in miri.
                     // If, however, the compiler ever starts transforming unchecked intrinsics into unchecked binops,
                     // we have to go back to just ignoring the overflow here.
                     return Err(EvalError::OverflowingMath);

src/memory.rs

@@ -166,7 +166,7 @@ pub struct Memory<'a, 'tcx> {
     /// We mark memory as "packed" or "unaligned" for a single statement, and clear the marking
     /// afterwards. In the case where no packed structs are present, it's just a single emptyness
     /// check of a set instead of heavily influencing all memory access code as other solutions
-    /// would.  This is simpler than the alternative of passing a "packed" parameter to every
+    /// would. This is simpler than the alternative of passing a "packed" parameter to every
     /// load/store method.
     ///
     /// One disadvantage of this solution is the fact that you can cast a pointer to a packed