Remove use of "Dynamicism"

Author: lattner

docs/OptimizationTips.rst

@@ -54,8 +54,8 @@ this mode will most likely take longer to compile, but may run faster.
 This mode can be enabled using the Xcode build setting 'Whole Module Optimization'.
 
 
-Limiting Language Dynamicism
-============================
+Reducing Dynamic Dispatch
+=========================
 
 Swift by default is a very dynamic language like Objective-C. Unlike Objective
 C, Swift gives the programmer the ability to improve runtime performance when