Merge branch 'jh/userdiff-python-async'

The userdiff machinery has been taught that "async def" is another
way to begin a "function" in Python.

* jh/userdiff-python-async:
  userdiff: support Python async functions

t/t4018/python-async-def

@@ -0,0 +1,4 @@
+async def RIGHT(pi: int = 3.14):
+    while True:
+        break
+    return ChangeMe()

t/t4018/python-class

@@ -0,0 +1,4 @@
+class RIGHT(int, str):
+    # comment
+    # another comment
+    # ChangeMe

t/t4018/python-def

@@ -0,0 +1,4 @@
+def RIGHT(pi: int = 3.14):
+    while True:
+        break
+    return ChangeMe()

t/t4018/python-indented-async-def

@@ -0,0 +1,7 @@
+class Foo:
+    async def RIGHT(self, x: int):
+        return [
+            1,
+            2,
+            ChangeMe,
+        ]

t/t4018/python-indented-class

@@ -0,0 +1,5 @@
+if TYPE_CHECKING:
+    class RIGHT:
+        # comment
+        # another comment
+        # ChangeMe

t/t4018/python-indented-def

@@ -0,0 +1,7 @@
+class Foo:
+    def RIGHT(self, x: int):
+        return [
+            1,
+            2,
+            ChangeMe,
+        ]

userdiff.c

@@ -145,7 +145,7 @@ PATTERNS("php",
 	 "[a-zA-Z_][a-zA-Z0-9_]*"
 	 "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
 	 "|[-+*/<>%&^|=!.]=|--|\\+\\+|<<=?|>>=?|===|&&|\\|\\||::|->"),
-PATTERNS("python", "^[ \t]*((class|def)[ \t].*)$",
+PATTERNS("python", "^[ \t]*((class|(async[ \t]+)?def)[ \t].*)$",
 	 /* -- */
 	 "[a-zA-Z_][a-zA-Z0-9_]*"
 	 "|[-+0-9.e]+[jJlL]?|0[xX]?[0-9a-fA-F]+[lL]?"