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

llvm-svn: 135375
diff --git a/llvm/lib/Transforms/Instrumentation/EdgeProfiling.cpp b/llvm/lib/Transforms/Instrumentation/EdgeProfiling.cpp
index 1d31fcc..e8ef265 100644
--- a/llvm/lib/Transforms/Instrumentation/EdgeProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/EdgeProfiling.cpp
@@ -74,7 +74,7 @@
     }
   }
 
-  const Type *ATy = ArrayType::get(Type::getInt32Ty(M.getContext()), NumEdges);
+  Type *ATy = ArrayType::get(Type::getInt32Ty(M.getContext()), NumEdges);
   GlobalVariable *Counters =
     new GlobalVariable(M, ATy, false, GlobalValue::InternalLinkage,
                        Constant::getNullValue(ATy), "EdgeProfCounters");