RFR: 8257467: [TESTBUG] -Wdeprecated-declarations is reported at sigset() in exesigtest.c [v4]

[Yasumasa Suenaga]

> `sigset()` is deprecated, and `__attribute_deprecated_msg__` has been [set to the declaration in glibc](https://sourceware.org/git/?p=glibc.git;a=commit;f=signal/signal.h;h=02802fafcf6e11ea3f998f685035ffe568dfddeb)
> 
> We can see the warning on `make test-image` as below:
> 
> * Fedora 33 x86_64
>     * gcc: gcc-10.2.1-6.fc33.x86_64
>     * glibc: glibc-2.32-2.fc33.x86_64
> 
> 
> 
>   245 | sigset(signal_num, handler);
>       | ^~~~~~
> In file included from /home/ysuenaga/github-forked/jdk/test/hotspot/jtreg/runtime/signal/exesigtest.c:25:
> 
>   353 | extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW
>       | ^~~~~~
> cc1: all warnings being treated as errors
> gmake[3]: *** [test/JtregNativeHotspot.gmk:1525: /home/ysuenaga/github-forked/jdk/build/linux-x86_64-server-fastdebug/support/test/hotspot/jtreg/native/support/exesigtest/exesigtest.o] Error 1
> gmake[3]: *** Waiting for unfinished jobs....
> gmake[2]: *** [make/Main.gmk:612: build-test-hotspot-jtreg-native] Error 2

Yasumasa Suenaga has updated the pull request incrementally with one additional commit since the last revision:

  Revert "Remove sigset() from signal handler tests"
  
  This reverts commit 21437c3a3fe043a95c47c18f9adc3f5c59109ccc.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1529/files
  - new: https://git.openjdk.java.net/jdk/pull/1529/files/19c35bba..f2ca9e5e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1529&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1529&range=02-03

  Stats: 89 lines in 3 files changed: 48 ins; 3 del; 38 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1529.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1529/head:pull/1529

PR: https://git.openjdk.java.net/jdk/pull/1529