[ripper] fix mismatched indentations warning [Bug #16981]

	The scanner location has to be set from `lex.ptok` before it is
	flushed by dispatching the scanner event.

	brace the fact that lchmod(2) can EOPNOTSUPP

	Musl libc has this function as a tiny wrapper of fchmodat(3posix).  On
	the other hand Linux kernel does not support changing modes of a symlink.
	The operation always fails with EOPNOTSUPP.  This fchmodat behaviour is
	defined in POSIX.  We have to take care of such exceptions.

	configure: suppress icc warnings

	Every time a pointer to/from VALUE conversion happens, these two
	warnings are issued:

	- warning ruby#1684: conversion from pointer to same-sized integral type (potential portability problem)
	- warning ruby#2312: pointer cast involving 64-bit pointed-to type

	Thank you, but we are well aware of the "potential portability problem".
	Let us ignore them all.

	disable to show the maximum number of threads.

	On Deiban 9 environment, the thread tests failed and
	this maximum threads information can finish up the machine
	resources. To check it, I turned-off showing this information.

	Skip jit_test on some new RubyCI envs for now

	Propagate JIT skip to all tests

parser to support that.

As mentioned in the referenced GitHub issue, we should use the OpenSSL
API instead of implementing the parsing logic ourselves, but it will
need backwards-incompatible changes which we can't backport to stable
versions. So continue to use the Ruby implementation for now.

References:
  ruby/openssl#208
  ruby/openssl#216

The original patch was written by Kazuki Yamaguchi <k@rhe.jp> and
the patch for ruby_2_7 branch was prepared by Vít Ondruch.

It has the same issue as RHEL 8.  k0kubun said he will fix later

This commit just adds dockerfiles we can run to ensure this repo doesn't
have a network dependency when we compile and install.  I also added the
files necessary to eliminate the network dependency.