merge revision(s) r39290:

	* lib/mkmf.rb: remove extra topdir in VPATH, which was in
	  win32/Makefile.sub for some reason and moved from there.
	  [ruby-dev:46998] [Bug #7864]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39420 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) r39255:

	* configure.in: Fix a bug introduced in r38342 that the cflagspat
	  substitution is messed up by the way CFLAGS and optflags are
	  modified, which affected FreeBSD and NetBSD/amd64 when
	  configured to use libexecinfo.  This bug resulted in CFLAGS and
	  CXXFLAGS in RbConfig::CONFIG having warnflags expanded in them,
	  forcing third-party C/C++ extensions to follow what warnflags
	  demands, like ANSI/ISO-C90 conformance.  ref [Bug #7101]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39421 b2dd03c8-39d4-4d8f-98ff-823fe69b080e