* Remove obsoleted opt_call_c_function insn

* Keep opt_call_c_function with DEFINE_INSN_IF

According to MSVC manual (*1), cl.exe can skip including a header file
when that:

- contains #pragma once, or
- starts with #ifndef, or
- starts with #if ! defined.

GCC has a similar trick (*2), but it acts more stricter (e. g. there
must be _no tokens_ outside of #ifndef...#endif).

Sun C lacked #pragma once for a looong time.  Oracle Developer Studio
12.5 finally implemented it, but we cannot assume such recent version.

This changeset modifies header files so that each of them include
strictly one #ifndef...#endif.  I believe this is the most portable way
to trigger compiler optimizations. [Bug #16770]

*1: https://docs.microsoft.com/en-us/cpp/preprocessor/once
*2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html

for simplicity and consistency.

Now SUPPORT_JOKE needs to be prefixed with OPT_ to make the config
visible in `RubyVM::VmOptsH`, and the inconsistency was introduced.

As it has never been available for override in configure (no #ifndef
guard), it should be fine to rename the config.

with mjit_compile.c (tool/ruby_vm/views/_mjit_compile_getivar.erb).

mjit_compile.c: ditto
tool/ruby_vm/views/_mjit_compile_getivar.erb: ditto
vm_opts.h: ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65074 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* insns.def (opt_send_without_block): reorder insn position because
  `opt_str_freeze` insn refer this insn (function) when
  OPT_CALL_THREADED_CODE is true.

* vm_opts.h (OPT_THREADED_CODE): introduce new macro to select
  threaded code implementation with a compile option (-D...).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64854 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* iseq.h (rb_compile_option_struct): trace instruction is removed so that
  remove the trace_instruction compile option.
  Don't show warning (just ignore) for Ruby 2.5.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61450 b2dd03c8-39d4-4d8f-98ff-823fe69b080e