swift234

Improve the compile time of the specializer.
The specializer creates new functions with a new name. Our method for finding if this name is available was to use Module::Lookup, which performed an O(n) search over the module. Since O(N/c) of the functions were specialized we had an O(N^2) search.
This patch saves the names of the function in the module prior to specialization and uses this list whever we need to generate a new name.



Swift SVN r11625