Alpine Linux fails to build when --with-source-date enabled

If "reproducible-builds" is enabled using the --with-source-date configure argument, the build fails on Alpine Linux with the following error:
14:42:34 Compiling 31 files for BUILD_JRTFS
14:42:38 Creating support/modules_libs/java.base/jrt-fs.jar
14:42:38 option --date requires an argument
14:42:38 Try `jar --help' for more information.
14:42:38 gmake[3]: *** [JrtfsJar.gmk:71: /home/adoptopenjdk/workspace/build-scripts/jobs/jdk/jdk-alpine-linux-x64-hotspot/workspace/build/src/build/linux-x86_64-server-release/support/modules_libs/java.base/jrt-fs.jar] Error 1
14:42:38 gmake[2]: *** [make/Main.gmk:394: jrtfs-jar] Error 2
14:42:38 gmake[2]: *** Waiting for unfinished jobs....

The reason is because Alpine Linux uses the BusyBox "date" tool, which is GNU compatible but the current openjdk make date version detection thinks it is BSD compatible and not GNU.