huc: main.c: include startup/globals at the appropriate time

Before this commit, startup.asm and globals.h were included at a time when
parsing of the first .c file had already started. This worked with the
assembly file because it does not depend on the C parser, but broke
horribly when there was a globals.h file.

Signed-off-by: Ulrich Hecht <ulrich.hecht@gmail.com>