qtdeclarative: enable QML JIT for Redox with Q_OS_REDOX platform fix

Two changes needed to enable Qt6 QML V4 JIT on Redox:
1. -DQT_FEATURE_qml_jit=ON (was OFF)
2. sed patch adding Q_OS_REDOX to qv4assemblercommon_p.h X86_64 SysV list

Without #2, the JIT PlatformAssemblerBase typedef is never defined
for Redox, causing Address/RegisterID/Jump type errors during compilation.

local/recipes/qt/qtdeclarative/recipe.toml

@@ -191,6 +191,12 @@ function(qt_internal_add_shader_helpers target name)
 endfunction()
 EOFCMAKE
 
+# QML JIT: add Q_OS_REDOX to X86_64 SysV assembler platform list.
+# Without this, Q_OS_REDOX isn't recognized and PlatformAssemblerBase is
+# never typedef'd, causing Address/RegisterID/Jump type errors.
+JIT_H="${COOKBOOK_SOURCE}/src/qml/jit/qv4assemblercommon_p.h"
+sed -i 's/|| defined(Q_OS_HURD)/|| defined(Q_OS_HURD) || defined(Q_OS_REDOX)/' "${JIT_H}"
+
 cmake "${COOKBOOK_SOURCE}" \
     -C "${COOKBOOK_BUILD}/shader_stub.cmake" \
     -DCMAKE_TOOLCHAIN_FILE="${COOKBOOK_ROOT}/local/recipes/qt/redox-toolchain.cmake" \
@@ -202,7 +208,7 @@ cmake "${COOKBOOK_SOURCE}" \
     -DQT_BUILD_EXAMPLES=OFF \
     -DQT_BUILD_TESTS=OFF \
 -DQT_GENERATE_SBOM=OFF \
--DQT_FEATURE_qml_jit=OFF \
+-DQT_FEATURE_qml_jit=ON \
 -DQT_FEATURE_ssl=OFF \
     -DQT_FEATURE_network=OFF \
     -DQT_FEATURE_localserver=OFF \