Use the host javac for bootstrapping
Use the host javac for bootstrapping

now that the bootstrap build uses the VanillaJavaBuilder it is compatible
with the host JDK's javac, and avoiding -Xbootclasspath/p makes the
bootstrap build more compatible with JDK 9.

See #5521

RELNOTES: N/A
PiperOrigin-RevId: 205605294

aehlig/bazel,meteorcloudy/bazel,akira-baruah/bazel,dslomov/bazel,safarmer/bazel,cushon/bazel,safarmer/bazel,meteorcloudy/bazel,dslomov/bazel-windows,ulfjack/bazel,meteorcloudy/bazel,perezd/bazel,cushon/bazel,twitter-forks/bazel,ulfjack/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,perezd/bazel,werkt/bazel,werkt/bazel,werkt/bazel,dslomov/bazel,werkt/bazel,akira-baruah/bazel,twitter-forks/bazel,ulfjack/bazel,safarmer/bazel,dropbox/bazel,twitter-forks/bazel,bazelbuild/bazel,aehlig/bazel,davidzchen/bazel,bazelbuild/bazel,twitter-forks/bazel,cushon/bazel,katre/bazel,ButterflyNetwork/bazel,katre/bazel,perezd/bazel,davidzchen/bazel,twitter-forks/bazel,dropbox/bazel,davidzchen/bazel,meteorcloudy/bazel,perezd/bazel,perezd/bazel,katre/bazel,aehlig/bazel,cushon/bazel,dslomov/bazel-windows,dslomov/bazel-windows,akira-baruah/bazel,akira-baruah/bazel,dslomov/bazel-windows,dropbox/bazel,davidzchen/bazel,ulfjack/bazel,akira-baruah/bazel,safarmer/bazel,dslomov/bazel-windows,ButterflyNetwork/bazel,katre/bazel,cushon/bazel,aehlig/bazel,ButterflyNetwork/bazel,dropbox/bazel,katre/bazel,bazelbuild/bazel,bazelbuild/bazel,safarmer/bazel,ulfjack/bazel,meteorcloudy/bazel,dslomov/bazel,werkt/bazel,dropbox/bazel,cushon/bazel,meteorcloudy/bazel,safarmer/bazel,davidzchen/bazel,dslomov/bazel-windows,dslomov/bazel,dropbox/bazel,perezd/bazel,aehlig/bazel,akira-baruah/bazel,ButterflyNetwork/bazel,aehlig/bazel,ButterflyNetwork/bazel,davidzchen/bazel,bazelbuild/bazel,bazelbuild/bazel,werkt/bazel,davidzchen/bazel,dslomov/bazel,ulfjack/bazel,ulfjack/bazel,dslomov/bazel,twitter-forks/bazel,perezd/bazel,aehlig/bazel,dslomov/bazel,twitter-forks/bazel,katre/bazel