version.c: show +JIT when --jit is passed

in version output.
version.h: ditto
ruby.c: propagate option for it
common.mk: updated dependency for version.c

mjit.c: overwrites the RUBY_DESCRIPTION to have +JIT when --jit is passed

test/ruby/test_rubyoptions.rb: add test for them

Only `ruby --jit -v` will have "+JIT", but this is intentional.
This may not be convenient for debugging by ticket with `ruby -v`,
but it's convenient for benchmark tools that pass options (--jit)
when showing it. At least such behavior is planned for benchmark_driver.gem
and this behavior is designed for it. Other benchmark tools are
recommended to follow the behavior too if they show version.
RUBY_DESCRIPTION might be useful for it too.

The position of "+JIT" is changed from original proposal because other
platforms like JRuby and TruffleRuby end it with archtecture.
It's made similar to JRuby, but it's upper-cased because Matz made approval
for "+JIT" in the ticket.

Example:
$ ruby -v
ruby 2.6.0dev (2018-02-22 trunk 62529) [x86_64-linux]
$ ruby --jit -v
ruby 2.6.0dev (2018-02-22 trunk 62529) +JIT [x86_64-linux]

After --jit is made default in the future, this output may be removed.
So do not rely on this output if possible.

[Feature #14462]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62530 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 0 deletions

diff --git a/common.mk b/common.mk
index 69ab1a0733..d4a5b54091 100644
--- a/common.mk
+++ b/common.mk
@@ -2847,9 +2847,11 @@ version.$(OBJEXT): {$(VPATH)}config.h
 version.$(OBJEXT): {$(VPATH)}defines.h
 version.$(OBJEXT): {$(VPATH)}intern.h
 version.$(OBJEXT): {$(VPATH)}missing.h
+version.$(OBJEXT): {$(VPATH)}mjit.h
 version.$(OBJEXT): {$(VPATH)}st.h
 version.$(OBJEXT): {$(VPATH)}subst.h
 version.$(OBJEXT): {$(VPATH)}version.c
+version.$(OBJEXT): {$(VPATH)}vm_core.h
 vm.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 vm.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
 vm.$(OBJEXT): $(CCAN_DIR)/list/list.h