cmd/5a, cmd/6a, cmd/8a: fix .y files to match y.tab.[ch]

cmd/5a, cmd/6a, cmd/8a: fix .y files to match y.tab.[ch]

When I renamed LAddr back to Addr (before sending the
original linker CLs), I missed the .y files in my global substitute.
Since the .y files are only processed when running make in
one of those directories (not during all.bash), they were
behind the generated files.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/40770044