This simple commit should improve performance of the generated program
sensibly. Basically all the global variables will have internal linkage
from now on (unless the `--external` parameter is specified on the
command line). This way, the compiler will be able to avoid load/store
instructions when leaving code in the current translation unit.
This commit introduces a docs target which translates `.rst` files into
man pages or HTML documents and installs them in `/usr/share/man/man1`
or `/usr/share/doc/revamb`.
Update `GeneratedIRReference.rst:` to reflect recent changes to the
`root` function. Specifically, the presence of the stack pointer
argument and initialization of the program counter and the stack
pointer.
`FromIRToExecutable.rst` has been updated too, to take into account the
new way we link `support.c`.
Finally, the `--tracing` argument has been removed from
`RevambUsage.rst` and the `-trace` argument is no documented in
`TranslateUsage.rst`.
Alessandro Di Federico