Do not consider deprecated functions as errors for core C extensions

* This was problematic for extconf.rb checks as they would think such deprecated functions do not exist.
  Notably it caused the openssl extconf.rb for openssl 3.4.0 to think there is no
  TS_VERIFY_CTS_set_certs() and then openssl_missing.h would redefine it, causing a compilation error.
* CRuby does not set -Werror for core C extensions, maybe we should not either.
  OTOH it is useful to notice new warnings in core C extensions, even more with mx hiding the output by default now.
* Note that changing $warnflags or $defs only affects the Makefile, but not the have_func() checks.
* Fixes #3724

CHANGELOG.md

@@ -8,6 +8,7 @@ Bug fixes:
 
 * Fix `Module#name` called inside the `Module#const_added` callback when the module is defined in the top-level scope (#3683, @andrykonchin).
 * Fix duplicated calls of a `Module#const_added` callback when a module with nested modules is assigned to a constant (@andrykonchin).
+* Support OpenSSL 1.1-3.4 and prefer in order OpenSSL 3.0.x, 3.x and 1.1 (EOL). There was a compilation issue with OpenSSL 3.4 (#3724, @eregon).
 
 Compatibility:
 

lib/cext/include/truffleruby/truffleruby-abi-version.h

@@ -20,6 +20,6 @@
 // $RUBY_VERSION must be the same as TruffleRuby.LANGUAGE_VERSION.
 // $ABI_NUMBER starts at 1 and is incremented for every ABI-incompatible change.
 
-#define TRUFFLERUBY_ABI_VERSION "3.3.5.7"
+#define TRUFFLERUBY_ABI_VERSION "3.3.5.8"
 
 #endif

lib/truffle/rbconfig.rb

@@ -145,6 +145,9 @@ module RbConfig
 
     warnflags << '-Wundef' # Warn for undefined preprocessor macros for core C extensions
     warnflags << '-Werror' # Make sure there are no warnings in core C extensions
+    # If there are deprecations in core C extensions, do not error for them.
+    # This would be problematic for extconf.rb checks as they would think such deprecated functions do not exist.
+    warnflags << '-Wno-error=deprecated-declarations'
   else
     libtruffleruby = "#{cext_dir}/libtruffleruby.#{soext}"
     libtrufflerubytrampoline = "#{cext_dir}/libtrufflerubytrampoline.#{soext}"

src/main/c/openssl/extconf.rb

@@ -13,11 +13,6 @@
 
 require "mkmf"
 
-if defined?(::TruffleRuby)
-  # Needed with libssl 3.0.0 and -Werror from building core C extensions
-  $warnflags += ' -Wno-deprecated-declarations'
-end
-
 ssl_dirs = nil
 if defined?(::TruffleRuby)
   # Always respect the openssl prefix chosen by truffle/openssl-prefix