Fix typo in ErrorHandlingRationale.rst

Author: S2Ler

Diff for: docs/ErrorHandlingRationale.rst

@@ -577,7 +577,7 @@ they produce, and so many errors just end up falling into broad
 buckets.  Different libraries end up with their own library-specific
 general error classes, and exceptions list end up just restating the
 library's own dependencies or wrapping the underlying errors in ways
-that loses criticial information.
+that loses critical information.
 
 
 Tradeoffs of typed propagation
@@ -768,7 +768,7 @@ not free:
   which on our platforms means a function call because we're not
   willing to commit to anything more specific in the ABI.
 
-* Jumping across arbitary frames invalidates the callee-save
+* Jumping across arbitrary frames invalidates the callee-save
   registers, so the registering frame must save them all eagerly.  In
   calling conventions with many callee-save registers, this can be
   very expensive.  However, this is only necessary when it's possible