Do "PAGESEL _main" prior to "GOTO _main"

I'm working on a pic16f887 program that (now) occupies more than one code page. Development was going fine until the code size went slightly over one page. As soon as that happened, the application code stopped working. Debugging revealed that execution never got to the application's main(). (I added code to pulse certain output pins and observed that the pulses were never occurring.)

It turned out that it's necessary to execute a "PAGESEL _main" prior to doing the "goto _main" at the end of _sdcc_gsinit_startup().

I've included a suitable ChangeLog entry at the beginning of the small (one line) patch.