[PR target/78213] Do not ICE on non-empty -fself-test

[Jakub Jelinek]

On Fri, Nov 11, 2016 at 09:10:48AM -0800, Aldy Hernandez wrote:
> The problem in this PR is that -fself-test is being run on a non empty
> source file.  This causes init_emit() to run, which sets:
> 
> 	REG_POINTER (virtual_incoming_args_rtx) = 1;
> 
> Setting REG_POINTER on the virtual incoming args, causes /f to be printed on
> some RTL dumps, causing the -fself-test machinery to fail at matching the
> expected value.
> 
> It looks that by design -fself-test is meant to be run before any
> initialization like the aforementioned runs.

Won't -fself-test -fno-syntax-only still crash?  I.e. wouldn't it be better
to deal with this e.g. in finish_options?  Or perhaps error out if
-fself-tests is not used with -fsyntax-only and change the Makefile to
invoke it with both options?

	Jakub