This fixes an issue addressed in 651f5a37f5b8 on FreeBSD 12.

The problem manifested itself as:

configuring Ruby module
checking for -fdeclspec ... found
checking for Ruby library ... not found
checking for Ruby library in /usr/local/lib ... not found

./configure: error: no Ruby found.

Future releases of GCC are planning to remove[0] default support for
some old features that were removed from C99 but GCC still accepts.

We can test for these changes by using the following -Werror=
directives

  -Werror=implicit-int
  -Werror=implicit-function-declaration
  -Werror=int-conversion
  -Werror=strict-prototypes
  -Werror=old-style-definition

Doing so revealed an issue with the auto/ tests in that the test
programs always define main as

  int main()

rather than

  int main(void)

which results in a bunch of errors like

build/autotest.c:3:23: error: function declaration isn't a prototype [-Werror=strict-prototypes]
    3 |                   int main() {
      |                       ^~~~
build/autotest.c: In function 'main':
build/autotest.c:3:23: error: old-style function definition [-Werror=old-style-definition]

The fix was easy, it only required fixing the main prototype with

  find -type f -exec sed -i 's/int main() {/int main(void) {/g' {} \;

Regardless of these upcoming GCC changes, this is probably a good thing
to do anyway for correctness.

[0]: https://fedoraproject.org/wiki/Changes/PortingToModernC

Link: <https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/CJXKTLXJUPZ4F2C2VQOTNMEA5JAUPMBD/>
Link: <https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/6SGHPHPAXKCVJ6PUZ57WVDQ5TDBVIRMF/>
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

PHP 8.2 changed the prototype of the function, removing the last
parameter.

Signed-off-by: Remi Collet <remi@remirepo.net>
Cc: Timo Stark <t.stark@nginx.com>
Cc: George Peter Banyard <girgias@php.net>
Tested-by: Andy Postnikov <apostnikov@gmail.com>
Acked-by: Andy Postnikov <apostnikov@gmail.com>
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>

Add -fdeclspec to NXT_RUBY_CFLAGS for Clang, if it's available.

Clang incorrectly reports 1 for __has_declspec_attribute(x) in
some cases, such as MacOS or Cygwin.  That causes ruby code to
break.  ruby added -fdeclspec to their CFLAGS in 2019 to
workaround this bug, since it enables __declspec() and therefore,
the compiler behavior matches what it reports.

Since we don't know what are all the architectures that trigger
the clang bug, let's add the flag for all of them (especially
since it should be harmless).

Add this workaround only at the time of configuring the ruby
module.  This way we don't clutter the global NXT_CFLAGS with an
unnecessary flag.

Link: unit bug <https://github.com/nginx/unit/issues/653>
Link: ruby bug <https://bugs.ruby-lang.org/issues/18616>
Link: LLVM bug <https://github.com/llvm/llvm-project/issues/49958>
Commit: LLVM: Add -fdeclspec <d170c4b57a91adc74ca89c6d4af616a00323b12c>
Commit: ruby: Use -fdeclspec <0958e19ffb047781fe1506760c7cbd8d7fe74e57>

The patch removes the "files" section from package.json to avoid future issues
with missing files.  For package testing purposes, 'npm pack' is used instead
of plain 'tar' to simulate packaging more accurately.

In Go 1.16, the module-aware mode is enabled by default; to fall back to
previous behavior, the GO111MODULE environment variable should be set to
'auto'.

Details: https://golang.org/doc/go1.16