[typetools/checker-framework] 957b39: Restrict instantiations of `@PolySigned` (#5127)

[Michael Ernst]

Branch: refs/heads/master
Home: https://github.com/typetools/checker-framework
Commit: 957b391a18480e2bc6dc5fa2bb49d43a2cd08f15
https://github.com/typetools/checker-framework/commit/957b391a18480e2bc6dc5fa2bb49d43a2cd08f15
Author: Michael Ernst <mer...@cs.washington.edu>
Date: 2022-04-26 (Tue, 26 Apr 2022)

Changed paths:
M checker-qual/src/main/java/org/checkerframework/checker/signedness/qual/PolySigned.java
M checker/src/main/java/org/checkerframework/checker/signedness/SignednessAnnotatedTypeFactory.java
A checker/tests/signedness/RestrictedPolymorphism.java
M docs/manual/creating-a-checker.tex
M docs/manual/generics.tex
M docs/manual/signedness-checker.tex

Log Message:
-----------
Restrict instantiations of `@PolySigned` (#5127)