merge revision(s) 39160: [Backport #8080]

	* configure.in: don't define ARCH_FLAG="-march=i486" if it causes
	  compilation problem.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39843 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 39162,39163: [Backport #8080]

	* configure.in: change CFLAGS temporally to test
	  ARCH_FLAG="-march=i486".


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39844 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 39198: [Backport #8080]

	* configure.in: move the test for -march=i486 just after
	  RUBY_UNIVERSAL_ARCH/RUBY_DEFAULT_ARCH.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39845 b2dd03c8-39d4-4d8f-98ff-823fe69b080e