[ruby-cvs:62504] nobu:r55340 (trunk): common.mk: fix win32/ifchange.bat usage

[nobu at ruby-lang.org]

nobu	2016-06-09 16:37:29 +0900 (Thu, 09 Jun 2016)

  New Revision: 55340

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=55340

  Log:
    common.mk: fix win32/ifchange.bat usage
    
    * common.mk: win32/ifchange.bat does not support input from stdin.
      also needs quotes to escape an equal sign.

  Modified files:
    trunk/common.mk