Graal import breaks AArch64 (and probably other non-Graal targets)

[Andrew Haley]

Building JVM variant 'server' with features 'all-gcs cds compiler1 compiler2 fprof jni-check jvmci jvmti management nmt services vm-structs'
make[3]: *** No rule to make target `/home/aph/hs/build/linux-aarch64-normal-server-release/buildtools/jdk.vm.compiler.match.processor.jar', needed by `/home/aph/hs/build/linux-aarch64-normal-server-release/support/gensrc/jdk.vm.compiler/_gensrc_proc_done'.
make[3]: *** No rule to make target `/home/aph/hs/build/linux-aarch64-normal-server-release/buildtools/jdk.vm.compiler.nodeinfo.processor.jar', needed by `/home/aph/hs/build/linux-aarch64-normal-server-release/support/gensrc/jdk.vm.compiler/_gensrc_proc_done'.
make[3]: *** No rule to make target `/home/aph/hs/build/linux-aarch64-normal-server-release/buildtools/jdk.vm.compiler.options.processor.jar', needed by `/home/aph/hs/build/linux-aarch64-normal-server-release/support/gensrc/jdk.vm.compiler/_gensrc_proc_done'.
make[3]: *** No rule to make target `/home/aph/hs/build/linux-aarch64-normal-server-release/buildtools/jdk.vm.compiler.replacements.verifier.jar', needed by `/home/aph/hs/build/linux-aarch64-normal-server-release/support/gensrc/jdk.vm.compiler/_gensrc_proc_done'.
make[3]: *** No rule to make target `/home/aph/hs/build/linux-aarch64-normal-server-release/buildtools/jdk.vm.compiler.serviceprovider.processor.jar', needed by `/home/aph/hs/build/linux-aarch64-normal-server-release/support/gensrc/jdk.vm.compiler/_gensrc_proc_done'.
make[3]: Target `default' not remade because of errors.
make[2]: *** [jdk.vm.compiler-gensrc-hotspot] Error 1

I understand that AArch64 isn't ready for Graal to be imported yet, but
the absence of Graal support should not break non-Graal targets.

Andrew.