Add doInitialization and doFinalization methods to ModulePass's, to allow them to be re-initialized and reused on multiple Module's.

Patch by Pedro Artigas.

llvm-svn: 168008

llvm/tools/llvm-extract/llvm-extract.cpp

@@ -276,7 +276,9 @@ int main(int argc, char **argv) {
   else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
     Passes.add(createBitcodeWriterPass(Out.os()));
 
+  Passes.doInitialization();
   Passes.run(*M.get());
+  Passes.doFinalization();
 
   // Declare success.
   Out.keep();