[Rd] RStartup.h: invalid parameter name: 'new' is a keyword

[Jeroen Ooms]

The latest r-devel / r-alpha includes a new definition:

   SA_TYPE R_SetSaveAction(SA_TYPE new);

But on Mac we see that packages that include the header now get:

  R_ext/RStartup.h:162:33: error: invalid parameter name: 'new' is a keyword