[passmanager] Change the optimizer to use SILOptFunctionBuilder.

I am going to add the code in a bit that does the notifications. I tried to pass
down the builder instead of the pass manager. I also tried not to change the
formatting.

rdar://42301529

lib/SILOptimizer/Transforms/GenericSpecializer.cpp

@@ -23,6 +23,7 @@
 #include "swift/SILOptimizer/Utils/Generics.h"
 #include "swift/SILOptimizer/Utils/Local.h"
 #include "swift/SILOptimizer/PassManager/Transforms.h"
+#include "swift/SILOptimizer/Utils/SILOptFunctionBuilder.h"
 #include "llvm/ADT/SmallVector.h"
 
 using namespace swift;
@@ -48,6 +49,7 @@ class GenericSpecializer : public SILFunctionTransform {
 } // end anonymous namespace
 
 bool GenericSpecializer::specializeAppliesInFunction(SILFunction &F) {
+  SILOptFunctionBuilder FunctionBuilder(*getPassManager());
   DeadInstructionSet DeadApplies;
   llvm::SmallSetVector<SILInstruction *, 8> Applies;
   OptRemark::Emitter ORE(DEBUG_TYPE, F.getModule());
@@ -101,7 +103,8 @@ bool GenericSpecializer::specializeAppliesInFunction(SILFunction &F) {
       // We have a call that can potentially be specialized, so
       // attempt to do so.
       llvm::SmallVector<SILFunction *, 2> NewFunctions;
-      trySpecializeApplyOfGeneric(Apply, DeadApplies, NewFunctions, ORE);
+      trySpecializeApplyOfGeneric(FunctionBuilder, Apply, DeadApplies,
+                                  NewFunctions, ORE);
 
       // Remove all the now-dead applies. We must do this immediately
       // rather than defer it in order to avoid problems with cloning