[16] RFR 8252250: isnanf is obsolete

[Aleksei Voitylov]

Hi,

in preparation for a review request for Alpine Linux JEP [1] it was
suggested [2] to send RFRs which are not specific to musl or busybox for
review upstream as separate patches.

Bug: https://bugs.openjdk.java.net/browse/JDK-8252250
Fix: http://cr.openjdk.java.net/~avoitylov/webrev.8252250/

ifnanf is obsolete [3], and musl does not define it. Proof of
correctness of replacement of isnanf with isnan for all practical
versions of gcc and llvm is provided in a comment to [4]. A backport of
this change to 14 passes JCK and shows no jtreg regressions on Linux.

Thanks,
-Aleksei


[1] https://openjdk.java.net/jeps/386
[2]
https://mail.openjdk.java.net/pipermail/portola-dev/2020-August/000471.html
[3] https://man7.org/linux/man-pages/man3/isnanf.3.html
[4] https://bugs.openjdk.java.net/browse/JDK-8178689