Update src/const_eval.md

Co-Authored-By: chriskrycho <hello@chriskrycho.com>

Author: Centril

src/const_eval.md

@@ -10,7 +10,7 @@ Certain forms of expressions, called constant expressions, can be evaluated at
 compile time. In [const contexts](#const-context), these are the only allowed
 expressions, and are always evaluated at compile time. In other places, such as
 [`let` statements](statements.html#let-statements), constant expressions are
-Errors such as out of bounds [array indexing] or [overflow] are compiler errors
+Behaviors such as out of bounds [array indexing] or [overflow] are compiler errors
 if the value must be evaluated at compile time (i.e. in const contexts).
 Otherwise, these behaviors are warnings, but will likely panic at run-time.