Bug 316129 – [CMake] Enable -Wunused-parameter on Cocoa to match Xcode

• Status: RESOLVED
• Resolution: FIXED
• Component: CMake

[zak ridouh]

The Cocoa CMake build globally suppressed -Wunused-parameter via
-Wno-unused-parameter in OptionsCocoa.cmake, even though -Wall -Wextra
already enables it. Xcode enables the warning everywhere (-Wextra in
CommonBase.xcconfig, treated as an error) and opts specific projects out
per-target via WK_FIXME_WARNING_CFLAGS.

Drop the blanket suppression so WTF, JavaScriptCore, WebCore, and PAL
warn like they do under Xcode, and add per-target opt-outs mirroring the
projects Xcode still exempts: WebKit (already present), WebKitLegacy,
DumpRenderTree, ImageDiff, and MiniBrowser. TestWebKitAPI and
WebKitTestRunner already opt out; the third-party targets build with -w.

WebKitLegacy's existing opt-out used add_compile_options(), which runs
after WEBKIT_FRAMEWORK_DECLARE creates the target and so never applied;
switch it to the target-scoped WEBKIT_ADD_TARGET_CXX_FLAGS form.

[Radar WebKit Bug Importer]

<rdar://problem/178557623>

[zak ridouh]

Pull request: https://github.com/WebKit/WebKit/pull/66293

[EWS]

Committed 314510@main (8d287629f85e): <https://commits.webkit.org/314510@main>

Reviewed commits have been landed. Closing PR #66293 and removing active labels.