RFR: 8317696: Fix compilation with clang-16 [v3]

[Jan Kratochvil]

> `--with-toolchain-type=clang` fails the compilation for me with `clang-16.0.6-3.fc38.x86_64`
> 
> While the warnings can be disabled I find better to just fix them. The GTK prototypes in JDK reported by clang are either missing or wrong. 
> 
> 
> src/java.base/unix/native/libnet/DefaultProxySelector.c:378:41: error: passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>     proxies = (*g_proxy_resolver_lookup)(resolver, uri, NULL, &error);
>                                         ^
> src/java.base/unix/native/libnet/DefaultProxySelector.c:397:63: error: passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>                                 (*g_network_address_parse_uri)(proxies[i], 0,
>                                                               ^
> src/java.base/unix/native/libnet/DefaultProxySelector.c:402:70: error: passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>                             phost = (*g_network_address_get_hostname)(conn);
>                                                                      ^
> src/java.base/unix/native/libnet/DefaultProxySelector.c:403:66: error: passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>                             pport = (*g_network_address_get_port)(conn);
>                                                                  ^
> src/java.base/unix/native/libnet/DefaultProxySelector.c:445:22: error: passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>         (*g_strfreev)(proxies);
>                      ^
> src/java.base/unix/native/libnet/DefaultProxySelector.c:448:25: error: passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>         (*g_clear_error)(&error);
>                         ^
> Compiling X11Renderer.c (for libawt_headless.so)
> In file included from src/java.desktop/unix/native/common/java2d/x11/X11PMBlitLoops.c:29:
> In file included from src/java.desktop/unix/native/common/java2d/x11/X11SurfaceData.h:29:
> src/java.desktop/unix/native/common/aw...

Jan Kratochvil has updated the pull request incrementally with one additional commit since the last revision:

  Remove declaration changes which are not required
   - suggested by djelinski

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16092/files
  - new: https://git.openjdk.org/jdk/pull/16092/files/6c2c2f87..fa2c32e4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16092&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16092&range=01-02

  Stats: 6 lines in 2 files changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/16092.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16092/head:pull/16092

PR: https://git.openjdk.org/jdk/pull/16092