Update math stub arguments reflect protocol support

Update math.factorial to reflect support for __int__ protocol.
Update other math functions to reflect support for __float__
protocol.

Author: brycepg

stdlib/2and3/math.pyi

@@ -1,7 +1,7 @@
 # Stubs for math
 # See: http://docs.python.org/2/library/math.html
 
-from typing import Tuple, Iterable, Optional
+from typing import Tuple, Iterable, Optional, SupportsFloat, SupportsInt
 
 import sys
 
@@ -13,57 +13,57 @@ if sys.version_info >= (3, 5):
 if sys.version_info >= (3, 6):
     tau = ...  # type: float
 
-def acos(x: float) -> float: ...
-def acosh(x: float) -> float: ...
-def asin(x: float) -> float: ...
-def asinh(x: float) -> float: ...
-def atan(x: float) -> float: ...
-def atan2(y: float, x: float) -> float: ...
-def atanh(x: float) -> float: ...
+def acos(x: SupportsFloat) -> float: ...
+def acosh(x: SupportsFloat) -> float: ...
+def asin(x: SupportsFloat) -> float: ...
+def asinh(x: SupportsFloat) -> float: ...
+def atan(x: SupportsFloat) -> float: ...
+def atan2(y: SupportsFloat, x: SupportsFloat) -> float: ...
+def atanh(x: SupportsFloat) -> float: ...
 if sys.version_info >= (3,):
-    def ceil(x: float) -> int: ...
+    def ceil(x: SupportsFloat) -> int: ...
 else:
-    def ceil(x: float) -> float: ...
-def copysign(x: float, y: float) -> float: ...
-def cos(x: float) -> float: ...
-def cosh(x: float) -> float: ...
-def degrees(x: float) -> float: ...
-def erf(x: float) -> float: ...
-def erfc(x: float) -> float: ...
-def exp(x: float) -> float: ...
-def expm1(x: float) -> float: ...
-def fabs(x: float) -> float: ...
-def factorial(x: int) -> int: ...
+    def ceil(x: SupportsFloat) -> float: ...
+def copysign(x: SupportsFloat, y: SupportsFloat) -> float: ...
+def cos(x: SupportsFloat) -> float: ...
+def cosh(x: SupportsFloat) -> float: ...
+def degrees(x: SupportsFloat) -> float: ...
+def erf(x: SupportsFloat) -> float: ...
+def erfc(x: SupportsFloat) -> float: ...
+def exp(x: SupportsFloat) -> float: ...
+def expm1(x: SupportsFloat) -> float: ...
+def fabs(x: SupportsFloat) -> float: ...
+def factorial(x: SupportsInt) -> int: ...
 if sys.version_info >= (3,):
-    def floor(x: float) -> int: ...
+    def floor(x: SupportsFloat) -> int: ...
 else:
-    def floor(x: float) -> float: ...
-def fmod(x: float, y: float) -> float: ...
-def frexp(x: float) -> Tuple[float, int]: ...
+    def floor(x: SupportsFloat) -> float: ...
+def fmod(x: SupportsFloat, y: SupportsFloat) -> float: ...
+def frexp(x: SupportsFloat) -> Tuple[float, int]: ...
 def fsum(iterable: Iterable) -> float: ...
-def gamma(x: float) -> float: ...
+def gamma(x: SupportsFloat) -> float: ...
 if sys.version_info >= (3, 5):
     def gcd(a: int, b: int) -> int: ...
-def hypot(x: float, y: float) -> float: ...
+def hypot(x: SupportsFloat, y: SupportsFloat) -> float: ...
 if sys.version_info >= (3, 5):
-    def isclose(a: float, b: float, rel_tol: float = ..., abs_tol: float = ...) -> bool: ...
-def isinf(x: float) -> bool: ...
+    def isclose(a: SupportsFloat, b: SupportsFloat, rel_tol: SupportsFloat = ..., abs_tol: SupportsFloat = ...) -> bool: ...
+def isinf(x: SupportsFloat) -> bool: ...
 if sys.version_info >= (3,):
-    def isfinite(x: float) -> bool: ...
-def isnan(x: float) -> bool: ...
-def ldexp(x: float, i: int) -> float: ...
-def lgamma(x: float) -> float: ...
-def log(x: float, base: float = ...) -> float: ...
-def log10(x: float) -> float: ...
-def log1p(x: float) -> float: ...
+    def isfinite(x: SupportsFloat) -> bool: ...
+def isnan(x: SupportsFloat) -> bool: ...
+def ldexp(x: SupportsFloat, i: int) -> float: ...
+def lgamma(x: SupportsFloat) -> float: ...
+def log(x: SupportsFloat, base: SupportsFloat = ...) -> float: ...
+def log10(x: SupportsFloat) -> float: ...
+def log1p(x: SupportsFloat) -> float: ...
 if sys.version_info >= (3, 3):
-    def log2(x: float) -> float: ...
-def modf(x: float) -> Tuple[float, float]: ...
-def pow(x: float, y: float) -> float: ...
-def radians(x: float) -> float: ...
-def sin(x: float) -> float: ...
-def sinh(x: float) -> float: ...
-def sqrt(x: float) -> float: ...
-def tan(x: float) -> float: ...
-def tanh(x: float) -> float: ...
-def trunc(x: float) -> int: ...
+    def log2(x: SupportsFloat) -> float: ...
+def modf(x: SupportsFloat) -> Tuple[float, float]: ...
+def pow(x: SupportsFloat, y: SupportsFloat) -> float: ...
+def radians(x: SupportsFloat) -> float: ...
+def sin(x: SupportsFloat) -> float: ...
+def sinh(x: SupportsFloat) -> float: ...
+def sqrt(x: SupportsFloat) -> float: ...
+def tan(x: SupportsFloat) -> float: ...
+def tanh(x: SupportsFloat) -> float: ...
+def trunc(x: SupportsFloat) -> int: ...