Added test cases for return in except statements.

tests/exception/tnestedreturn.nim

@@ -0,0 +1,40 @@
+discard """
+  file: "tnestedreturn.nim"
+  output: "A\nB\nC\n"
+"""
+
+# Various tests of return nested in double try/except statements
+
+proc test1() =
+
+  finally: echo "A"
+
+  try:
+    raise newException(EOS, "Problem")
+  except EOS:
+    return
+
+test1()
+
+
+proc test2() =
+
+  finally: echo "B"
+
+  try:
+    return
+  except EOS:
+    discard
+
+test2()
+
+proc test3() =
+  try:
+    try:
+      raise newException(EOS, "Problem")
+    except EOS:
+      return
+  finally:
+    echo "C"
+
+test3()