Merge pull request #23 from nstanke/patch-1

Fix typo

Author: tkremenek

include/swift/AST/Builtins.def

@@ -306,7 +306,7 @@ BUILTIN_SIL_OPERATION(FixLifetime, "fixLifetime", Special)
 ///   dynamic object type uses native swift reference counting:
 ///   (Builtin.UnknownObject, unknown class reference, class existential)
 ///
-/// - Bridged object types allow the dymanic object type check to be
+/// - Bridged object types allow the dynamic object type check to be
 ///   passed based on their pointer encoding:
 ///   (Builtin.BridgeObject)
 ///