land David Blaikie's patch to de-constify Type, with a few tweaks.

llvm-svn: 135375
diff --git a/llvm/unittests/ExecutionEngine/JIT/JITMemoryManagerTest.cpp b/llvm/unittests/ExecutionEngine/JIT/JITMemoryManagerTest.cpp
index 039b5e0..be5d152 100644
--- a/llvm/unittests/ExecutionEngine/JIT/JITMemoryManagerTest.cpp
+++ b/llvm/unittests/ExecutionEngine/JIT/JITMemoryManagerTest.cpp
@@ -22,7 +22,7 @@
 
 Function *makeFakeFunction() {
   std::vector<Type*> params;
-  const FunctionType *FTy =
+  FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(getGlobalContext()), params, false);
   return Function::Create(FTy, GlobalValue::ExternalLinkage);
 }