tests/ports/unix: Add coverage test for frozen functions and generators.

Signed-off-by: Damien George <damien@micropython.org>

ports/unix/variants/coverage/frzmpy/frzmpy4.py

@@ -0,0 +1,16 @@
+# Test importing frozen functions.
+
+# A simple bytecode function with no children.
+def f():
+    return 1
+
+
+print(__name__, f())
+
+
+# A simple bytecode generator with no children.
+def g():
+    yield 2
+
+
+print(__name__, next(g()))