Fixes: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=269906
I get the following warning when building it:
```
/usr/src/cddl/contrib/opensolaris/lib/libdtrace/common/dt_lex.l:410: warning, trailing context made variable due to preceding '|' action
/usr/src/cddl/contrib/opensolaris/lib/libdtrace/common/dt_lex.l:409: warning, dangerous trailing context
/usr/src/cddl/contrib/opensolaris/lib/libdtrace/common/dt_lex.l:409: warning, dangerous trailing context
yacc: 1 shift/reduce conflict.
```