add test with different const placement

Author: vbvictor

clang-tools-extra/test/clang-tidy/checkers/performance/unnecessary-value-param-templates.cpp

@@ -103,6 +103,12 @@ void ParameterPack(Args... args) {
   // CHECK-FIXES: void ParameterPack(const Args&... args) {
 }
 
+template <typename... Args>
+void ParameterPackConst(Args const... args) {
+  // CHECK-MESSAGES: [[@LINE-1]]:39: warning: the const qualified parameter 'args' of type 'const ExpensiveToCopyType'
+  // CHECK-FIXES: void ParameterPackConst(Args const&... args) {
+}
+
 template <typename... Args>
 void ParameterPackWithParams(const ExpensiveToCopyType E1, ExpensiveToCopyType E2, Args... args) {
   // CHECK-MESSAGES: [[@LINE-1]]:56: warning: the const qualified parameter 'E1'
@@ -117,6 +123,7 @@ void PackWithNonExpensive(int x, Args... args) {}
 void instantiatedParameterPack() {
   ExpensiveToCopyType E;
   ParameterPack(E);
+  ParameterPackConst(E);
   ParameterPackWithParams(E, E, E);
   PackWithNonExpensive(5, 5);
 }