[tree-ssa] Don't return but abort() in tree-ssa-ccp on non-GIMPLEwith checking enabled

[Steven Bosscher <s dot bosscher at student dot tudelft dot nl>]

We should never ever see non-GIMPLE at this point, so the return truely 
is lame.  But what's worse
is that this is the kind of thing that causes bugs that disappear with 
checking enabled but cause ICEs
with checking disabled.  Shouldn't _all_ checks in #if ENABLE_CHECKING 
abort if they fail?

Bootstrapped C/C++ on i686-pc-cygwin.  Not really obvious because I 
don't know the history of
this check, so... OK?

Gr.
Steven


2003-06-16  Steven Bosscher  <steven@gcc.gnu.org>

	* tree-ssa-ccp.c (visit_stmt): Die if something tries to make
	us visit a non-GIMPLE tree.

Index: tree-ssa-ccp.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-ssa-ccp.c,v
retrieving revision 1.1.2.73
diff -c -3 -p -r1.1.2.73 tree-ssa-ccp.c
*** tree-ssa-ccp.c	15 Jun 2003 07:18:01 -0000	1.1.2.73
--- tree-ssa-ccp.c	15 Jun 2003 22:20:46 -0000
*************** visit_stmt (tree stmt)
*** 472,478 ****
  #if defined ENABLE_CHECKING
    /* FIXME: This is lame.  All statements should be in GIMPLE form.  */
    if (TREE_NOT_GIMPLE (stmt))
!     return;
  #endif
  
    if (dump_file && (dump_flags & TDF_DETAILS))
--- 472,478 ----
  #if defined ENABLE_CHECKING
    /* FIXME: This is lame.  All statements should be in GIMPLE form.  */
    if (TREE_NOT_GIMPLE (stmt))
!     abort ();
  #endif
  
    if (dump_file && (dump_flags & TDF_DETAILS))