Prefer SmallVector::append/insert over push_back loops.

Same functionality, but hoists the vector growth out of the loop.

llvm-svn: 229500
diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
index ae1c228..6adf0d2 100644
--- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -371,10 +371,8 @@
 }
 
 FunctionType *DataFlowSanitizer::getArgsFunctionType(FunctionType *T) {
-  llvm::SmallVector<Type *, 4> ArgTypes;
-  std::copy(T->param_begin(), T->param_end(), std::back_inserter(ArgTypes));
-  for (unsigned i = 0, e = T->getNumParams(); i != e; ++i)
-    ArgTypes.push_back(ShadowTy);
+  llvm::SmallVector<Type *, 4> ArgTypes(T->param_begin(), T->param_end());
+  ArgTypes.append(T->getNumParams(), ShadowTy);
   if (T->isVarArg())
     ArgTypes.push_back(ShadowPtrTy);
   Type *RetType = T->getReturnType();
@@ -387,9 +385,8 @@
   assert(!T->isVarArg());
   llvm::SmallVector<Type *, 4> ArgTypes;
   ArgTypes.push_back(T->getPointerTo());
-  std::copy(T->param_begin(), T->param_end(), std::back_inserter(ArgTypes));
-  for (unsigned i = 0, e = T->getNumParams(); i != e; ++i)
-    ArgTypes.push_back(ShadowTy);
+  ArgTypes.append(T->param_begin(), T->param_end());
+  ArgTypes.append(T->getNumParams(), ShadowTy);
   Type *RetType = T->getReturnType();
   if (!RetType->isVoidTy())
     ArgTypes.push_back(ShadowPtrTy);