RFR: 8324809: compiler can crash with SOE while proving if two recursive types are disjoint [v2]

[Vicente Romero]

> javac is crashing with SOE while compiling code like:
> 
> 
> class Criteria<B extends Builder<? extends Criteria>> {
>     public <D extends Builder<E>, E extends Criteria<D>> D builder() {
>         return (D) new Builder<>();
>     }
> 
> }
> 
> class Builder<C extends Criteria<? extends Builder<C>>> {}
> 
> 
> here while attributing: `return (D)new Builder<>();` the compiler is trying to prove that: `Builder<C>` is castable to `D`, then as the upper bound of `D` is `Builder<E>`, we need to check if `Builder<C>` is castable to `Builder<E>`. Then the next step is to try to check if type variables C and E are disjoint. During this process is when the compiler gets out of resources given that
> 
> E <: Criteria<D>
> D <: Builder<E> here we have E again and we start over in an infinite loop,
> 
> Here the proposal is to detect cycles in the type arguments graph and accept these type of casts if we find a cycle and thus can't prove if two types are disjoint,
> 
> TIA

Vicente Romero has updated the pull request incrementally with one additional commit since the last revision:

  addressing review comments

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/19194/files
  - new: https://git.openjdk.org/jdk/pull/19194/files/a9027703..4ca4131e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19194&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19194&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/19194.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19194/head:pull/19194

PR: https://git.openjdk.org/jdk/pull/19194