[ruby-cvs:71299] k0kubun:r64207 (trunk): win32/Makefile.sub: remove RUBY_EXPORT macro

[k0kubun at ruby-lang.org]

k0kubun	2018-08-07 10:17:39 +0900 (Tue, 07 Aug 2018)

  New Revision: 64207

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=64207

  Log:
    win32/Makefile.sub: remove RUBY_EXPORT macro
    
    defined in XCFLAGS.
    
    This change resolves following link errors in MJIT:
    
    ```
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cObject
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cFalseClass
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cFloat
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cInteger
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cNilClass
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cProc
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cString
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cSymbol
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_cTrueClass
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_eArgError
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_eNoMethodError
    rb_mjit_header-2.6.0.obj : error LNK2001: unresolved external symbol rb_eNameError
    _ruby_mjit_p41476u0.obj : error LNK2001: unresolved external symbol rb_eFatal
    ```

  Modified files:
    trunk/win32/Makefile.sub