There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.

llvm-svn: 96344
diff --git a/llvm/tools/bugpoint/ExtractFunction.cpp b/llvm/tools/bugpoint/ExtractFunction.cpp
index 70011a7..eaa2c53 100644
--- a/llvm/tools/bugpoint/ExtractFunction.cpp
+++ b/llvm/tools/bugpoint/ExtractFunction.cpp
@@ -73,7 +73,7 @@
   Instruction *TheInst = RI;              // Got the corresponding instruction!
 
   // If this instruction produces a value, replace any users with null values
-  if (isa<StructType>(TheInst->getType()))
+  if (TheInst->getType()->isStructTy())
     TheInst->replaceAllUsesWith(UndefValue::get(TheInst->getType()));
   else if (TheInst->getType() != Type::getVoidTy(I->getContext()))
     TheInst->replaceAllUsesWith(Constant::getNullValue(TheInst->getType()));