Disable an "embedsignatures" test that is not actually valid with PEP 484 but...

Disable an "embedsignatures" test that is not actually valid with PEP 484 but fails to compile as the return type now interpreted as a C-tuple of Python objects (which is not supported).

tests/run/embedsignatures.pyx

@@ -81,7 +81,7 @@ __doc__ = ur"""
     Ext.m(self, a=u'spam')
 
     >>> print (Ext.n.__doc__)
-    Ext.n(self, a: int, b: float = 1.0, *args: tuple, **kwargs: dict) -> (None, True)
+    Ext.n(self, a: int, double b: float = 1.0, *args: tuple, **kwargs: dict) -> (None, True)
 
     >>> print (Ext.get_int.__doc__)
     Ext.get_int(self) -> int
@@ -403,7 +403,8 @@ cdef class Foo:
     def m03(self, a: 42, b: +42, c: -42) ->  int : pass  # XXX +42 -> 42
     def m04(self, a: 3.14, b: +3.14, c: -3.14) -> float : pass
     def m05(self, a: 1 + 2j, b: +2j, c: -2j) -> complex : pass
-    def m06(self, a: "abc", b: b"abc", c: u"abc") -> (str, bytes, unicode) : pass
+    # this is not a valid PEP 484 declaration, and Cython interprets it as a C-tuple
+    #def m06(self, a: "abc", b: b"abc", c: u"abc") -> (str, bytes, unicode) : pass
     def m07(self, a: [1, 2, 3], b: []) -> list: pass
     def m08(self, a: (1, 2, 3), b: ()) -> tuple: pass
     def m09(self, a: {1, 2, 3}, b: {i for i in ()}) -> set: pass
@@ -448,8 +449,8 @@ Foo.m04(self, a: 3.14, b: 3.14, c: -3.14) -> float
 >>> print(Foo.m05.__doc__)
 Foo.m05(self, a: 1 + 2j, b: +2j, c: -2j) -> complex
 
->>> print(Foo.m06.__doc__)
-Foo.m06(self, a: 'abc', b: b'abc', c: u'abc') -> (str, bytes, unicode)
+#>>> print(Foo.m06.__doc__)
+#Foo.m06(self, a: 'abc', b: b'abc', c: u'abc') -> (str, bytes, unicode)
 
 >>> print(Foo.m07.__doc__)
 Foo.m07(self, a: [1, 2, 3], b: []) -> list