Fix demangle helper after r286788

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292541 91177308-0d34-0410-b5e6-96231b3b80d8

test/support/demangle.h

@@ -34,9 +34,7 @@ inline std::string demangle(const char* mangled_name) {
 template <size_t N> struct Printer;
 inline std::string demangle(const char* mangled_name) {
   int status = 0;
-  std::string input(mangled_name);
-  input.insert(0, "_Z");
-  char* out = __cxxabiv1::__cxa_demangle(input.c_str(), nullptr, nullptr, &status);
+  char* out = __cxxabiv1::__cxa_demangle(mangled_name, nullptr, nullptr, &status);
   if (out != nullptr) {
     std::string res(out);
     std::free(out);

test/support/test.support/test_demangle.pass.cpp

@@ -20,7 +20,7 @@ int main() {
     const char* raw;
     const char* expect;
   } TestCases[] = {
-      {typeid(int).name(), "i"}, // FIXME
+      {typeid(int).name(), "int"},
       {typeid(MyType).name(), "MyType"},
       {typeid(ArgumentListID<int, MyType>).name(), "ArgumentListID<int, MyType>"}
   };