C#: Add some manual source neutrals.

Author: michaelnebel

csharp/ql/lib/ext/System.Configuration.model.yml

@@ -15,3 +15,8 @@ extensions:
       - ["System.Configuration", "SettingElementCollection", False, "Clear", "()", "", "Argument[this].WithoutElement", "Argument[this]", "value", "manual"]
       - ["System.Configuration", "SettingsPropertyCollection", False, "Clear", "()", "", "Argument[this].WithoutElement", "Argument[this]", "value", "manual"]
       - ["System.Configuration", "SettingsPropertyValueCollection", False, "Clear", "()", "", "Argument[this].WithoutElement", "Argument[this]", "value", "manual"]
+  - addsTo:
+      pack: codeql/csharp-all
+      extensible: neutralModel
+    data:
+      - ["System.Configuration", "ApplicationSettingsBase", "GetPreviousVersion", "(System.String)", "source", "manual"]

csharp/ql/lib/ext/System.Diagnostics.model.yml

@@ -22,3 +22,8 @@ extensions:
       - ["System.Diagnostics", "TraceListenerCollection", False, "get_Item", "(System.Int32)", "", "Argument[this].Element", "ReturnValue", "value", "manual"]
       - ["System.Diagnostics", "TraceListenerCollection", False, "get_Item", "(System.String)", "", "Argument[this].Element", "ReturnValue", "value", "manual"]
       - ["System.Diagnostics", "TraceListenerCollection", False, "set_Item", "(System.Int32,System.Diagnostics.TraceListener)", "", "Argument[1]", "Argument[this].Element", "value", "manual"]
+  - addsTo:
+      pack: codeql/csharp-all
+      extensible: neutralModel
+    data:
+      - ["System.Diagnostics", "Process", "get_ProcessName", "()", "source", "manual"]

csharp/ql/lib/ext/System.model.yml

@@ -870,3 +870,8 @@ extensions:
       - ["System", "ValueTuple<T1,T2>", False, "get_Item", "(System.Int32)", "", "Argument[this].Field[System.ValueTuple`2.Item2]", "ReturnValue", "value", "manual"]
       - ["System", "ValueTuple<T1>", False, "ValueTuple", "(T1)", "", "Argument[0]", "Argument[this].Field[System.ValueTuple`1.Item1]", "value", "manual"]
       - ["System", "ValueTuple<T1>", False, "get_Item", "(System.Int32)", "", "Argument[this].Field[System.ValueTuple`1.Item1]", "ReturnValue", "value", "manual"]
+  - addsTo:
+      pack: codeql/csharp-all
+      extensible: neutralModel
+    data:
+      - ["System", "Environment", "get_SystemDirectory", "()", "source", "manual"]