[jdk18u] RFR: 8284848: C2: Compiler blackhole arguments should be treated as globally escaping

[Vladimir Kozlov]

On Mon, 2 May 2022 11:11:14 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Unclean backport to improve Blackhole - EA interactions. The backport is not clean, because `IRNode` needs missing constants, and `set_escape_state` does not accept third argument (description) in 18u.
> 
> Additional testing:
>  - [x] `compiler/c2/irTests/blackhole` fail without the patch, pass with it
>  - [x] `compiler/blackhole` continue to pass

Good.

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

Marked as reviewed by kvn (Reviewer).

PR: https://git.openjdk.java.net/jdk18u/pull/118