Ruby

Add yjit.o to DTRACE_DEPENDENT_OBJS

In principle, we have a DTrace probe in yjit.c, so yjit.o should be
in DTRACE_DEPENDENT_OBJS for DTRACE_REBUILD=yes builds. This commit
adds to the list.

In practice DTRACE_REBUILD=yes implies the system has a Solaris-like
DTrace and YJIT doesn't support those systems. YJIT_OBJ expands to
nothing, and yjit.c isn't compiled.

I tested on OmniOS v11 r151034m with:

$ ../src/configure --with-out-ext=psych MAKE=gmake AR=ar debugflags=-g
$ gmake -j

It builds before and after this change.

[Bug #18480]