cext: reformat with clang-format 6.0

It appears some changes in clang-format affect our code. I didn't dig into
that deeper since the new output looks better.

mercurial/cext/pathencode.c

@@ -474,7 +474,10 b' static Py_ssize_t basicencode(char *dest'
 	static const uint32_t twobytes[8] = {0, 0, 0x87fffffe};
 
 	static const uint32_t onebyte[8] = {
-	    1, 0x2bff3bfa, 0x68000001, 0x2fffffff,
+	    1,
+	    0x2bff3bfa,
+	    0x68000001,
+	    0x2fffffff,
 	};
 
 	Py_ssize_t destlen = 0;