'out' or 'ref' usage in a cstype typemap in directors

'out' / 'ref' was not always stripped out in parts of the
director code generation.

Issue #1628

Examples/test-suite/csharp/Makefile.in

@@ -16,6 +16,7 @@ CPP_TEST_CASES = \
 	complextest \
 	csharp_attributes \
 	csharp_swig2_compatibility \
+	csharp_director_typemaps \
 	csharp_exceptions \
 	csharp_features \
 	csharp_lib_arrays \

Examples/test-suite/csharp/csharp_director_typemaps_runme.cs

@@ -0,0 +1,53 @@
+
+using System;
+using System.Reflection;
+using csharp_director_typemapsNamespace;
+
+public class csharp_director_typemaps_runme {
+
+  class CSharpDirectorTypemaps_InStreamDerived : InStream
+  {
+    private int constant;
+    public CSharpDirectorTypemaps_InStreamDerived(int constant) { this.constant = constant; }
+    public override int Read(global::System.IntPtr buf, int len, out int readLen) {
+      readLen = (buf == global::System.IntPtr.Zero) ? -len - constant : len + constant;
+      return readLen;
+    }
+    public override int Write(global::System.IntPtr buf, int len, out int writeLen) {
+      writeLen = (buf == global::System.IntPtr.Zero) ? -len - constant : len + constant;
+      return writeLen;
+    }
+  }
+  public static void Main() {
+    int outLen = -1;
+    int k = 100;
+    int j = 23;
+    InStream instream = new CSharpDirectorTypemaps_InStreamDerived(k);
+
+    {
+      int ret = csharp_director_typemaps.callRead(instream, InStream.getCPtr(instream).Handle, j, out outLen);
+      Assert(outLen, j + k);
+      Assert(ret, j + k);
+    }
+    {
+      int ret = csharp_director_typemaps.callRead(instream, global::System.IntPtr.Zero, j, out outLen);
+      Assert(outLen, -j - k);
+      Assert(ret, -j - k);
+    }
+
+    {
+      int ret = csharp_director_typemaps.callWrite(instream, InStream.getCPtr(instream).Handle, j, out outLen);
+      Assert(outLen, j + k);
+      Assert(ret, j + k);
+    }
+    {
+      int ret = csharp_director_typemaps.callWrite(instream, global::System.IntPtr.Zero, j, out outLen);
+      Assert(outLen, -j - k);
+      Assert(ret, -j - k);
+    }
+  }
+  private static void Assert(int i1, int i2) {
+    if (i1 != i2)
+      throw new Exception("assertion failure. " + i1 + " != " + i2);
+  }
+}