Revert "[lldb/API] Overwrite variables with SBLaunchInfo::SetEnvironment(append=true)"

This reverts commit 695b33a beacuse
it broke the macOS bot.

Author: Davide Italiano

lldb/source/API/SBLaunchInfo.cpp

@@ -190,10 +190,9 @@ void SBLaunchInfo::SetEnvironment(const SBEnvironment &env, bool append) {
   LLDB_RECORD_METHOD(void, SBLaunchInfo, SetEnvironment,
                      (const lldb::SBEnvironment &, bool), env, append);
   Environment &refEnv = env.ref();
-  if (append) {
-    for (auto &KV : refEnv)
-      m_opaque_sp->GetEnvironment().insert_or_assign(KV.first(), KV.second);
-  } else
+  if (append)
+    m_opaque_sp->GetEnvironment().insert(refEnv.begin(), refEnv.end());
+  else
     m_opaque_sp->GetEnvironment() = refEnv;
   m_opaque_sp->RegenerateEnvp();
 }

lldb/test/API/python_api/sbenvironment/TestSBEnvironment.py

@@ -53,11 +53,6 @@ def test_launch_info(self):
         launch_info.SetEnvironment(env, append=True)
         self.assertEqual(launch_info.GetEnvironment().GetNumValues(), env_count + 1)
 
-        env.Set("FOO", "baz", overwrite=True)
-        launch_info.SetEnvironment(env, append=True)
-        self.assertEqual(launch_info.GetEnvironment().GetNumValues(), env_count + 1)
-        self.assertEqual(launch_info.GetEnvironment().Get("FOO"), "baz")
-
         # Make sure we can replace the launchInfo's environment
         env.Clear()
         env.Set("BAR", "foo", overwrite=True)
@@ -125,11 +120,6 @@ def test_creating_and_modifying_environment(self):
         env.SetEntries(entries, append=False)
         self.assertEqualEntries(env, ["X=x", "Y=y"])
 
-        entries.Clear()
-        entries.AppendList(["X=y", "Y=x"], 2)
-        env.SetEntries(entries, append=True)
-        self.assertEqualEntries(env, ["X=y", "Y=x"])
-
         # Test clear
         env.Clear()
         self.assertEqualEntries(env, [])