Fix bug in bessel_jn for n == -1.

Add new test case.
Checked that the other Bessel functions do not have the same issue.
Checked that real-valued -1 argument is fixed OK as well as integer argument.
Fixes #2733.

[SVN r51059]

libs/math

@@ -1 +1 @@
-Subproject commit 34049f062448bb04805841ea48c17234f789831b
+Subproject commit 5fad227b2ae41a3949458ec54b0dbe99fe2f8ba6